diff --git a/irb.gemspec b/irb.gemspec
index b29002f59..a024210e7 100644
--- a/irb.gemspec
+++ b/irb.gemspec
@@ -41,6 +41,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = Gem::Requirement.new(">= 2.7")
 
+  spec.add_dependency "prism", ">= 1.0"
   spec.add_dependency "reline", ">= 0.4.2"
   spec.add_dependency "rdoc", ">= 4.0.0"
 end
diff --git a/lib/irb/color.rb b/lib/irb/color.rb
index fca942b28..872e6b6af 100644
--- a/lib/irb/color.rb
+++ b/lib/irb/color.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 require 'reline'
-require 'ripper'
+require 'prism'
 require_relative 'ruby-lex'
 
 module IRB # :nodoc:
@@ -18,64 +18,96 @@ module Color
     CYAN      = 36
     WHITE     = 37
 
-    TOKEN_KEYWORDS = {
-      on_kw: ['nil', 'self', 'true', 'false', '__FILE__', '__LINE__', '__ENCODING__'],
-      on_const: ['ENV'],
-    }
-    private_constant :TOKEN_KEYWORDS
-
-    # A constant of all-bit 1 to match any Ripper's state in #dispatch_seq
-    ALL = -1
-    private_constant :ALL
-
-    begin
-      # Following pry's colors where possible, but sometimes having a compromise like making
-      # backtick and regexp as red (string's color, because they're sharing tokens).
-      TOKEN_SEQ_EXPRS = {
-        on_CHAR:            [[BLUE, BOLD],            ALL],
-        on_backtick:        [[RED, BOLD],             ALL],
-        on_comment:         [[BLUE, BOLD],            ALL],
-        on_const:           [[BLUE, BOLD, UNDERLINE], ALL],
-        on_embexpr_beg:     [[RED],                   ALL],
-        on_embexpr_end:     [[RED],                   ALL],
-        on_embvar:          [[RED],                   ALL],
-        on_float:           [[MAGENTA, BOLD],         ALL],
-        on_gvar:            [[GREEN, BOLD],           ALL],
-        on_heredoc_beg:     [[RED],                   ALL],
-        on_heredoc_end:     [[RED],                   ALL],
-        on_ident:           [[BLUE, BOLD],            Ripper::EXPR_ENDFN],
-        on_imaginary:       [[BLUE, BOLD],            ALL],
-        on_int:             [[BLUE, BOLD],            ALL],
-        on_kw:              [[GREEN],                 ALL],
-        on_label:           [[MAGENTA],               ALL],
-        on_label_end:       [[RED, BOLD],             ALL],
-        on_qsymbols_beg:    [[RED, BOLD],             ALL],
-        on_qwords_beg:      [[RED, BOLD],             ALL],
-        on_rational:        [[BLUE, BOLD],            ALL],
-        on_regexp_beg:      [[RED, BOLD],             ALL],
-        on_regexp_end:      [[RED, BOLD],             ALL],
-        on_symbeg:          [[YELLOW],                ALL],
-        on_symbols_beg:     [[RED, BOLD],             ALL],
-        on_tstring_beg:     [[RED, BOLD],             ALL],
-        on_tstring_content: [[RED],                   ALL],
-        on_tstring_end:     [[RED, BOLD],             ALL],
-        on_words_beg:       [[RED, BOLD],             ALL],
-        on_parse_error:     [[RED, REVERSE],          ALL],
-        compile_error:      [[RED, REVERSE],          ALL],
-        on_assign_error:    [[RED, REVERSE],          ALL],
-        on_alias_error:     [[RED, REVERSE],          ALL],
-        on_class_name_error:[[RED, REVERSE],          ALL],
-        on_param_error:     [[RED, REVERSE],          ALL],
-        on___end__:         [[GREEN],                 ALL],
-      }
-    rescue NameError
-      # Give up highlighting Ripper-incompatible older Ruby
-      TOKEN_SEQ_EXPRS = {}
+    # Following pry's colors where possible
+    TOKEN_SEQS = {
+      KEYWORD_NIL:        [CYAN, BOLD],
+      KEYWORD_SELF:       [CYAN, BOLD],
+      KEYWORD_TRUE:       [CYAN, BOLD],
+      KEYWORD_FALSE:      [CYAN, BOLD],
+      KEYWORD___FILE__:   [CYAN, BOLD],
+      KEYWORD___LINE__:   [CYAN, BOLD],
+      KEYWORD___ENCODING__: [CYAN, BOLD],
+      CHARACTER_LITERAL:  [BLUE, BOLD],
+      BACKTICK:           [RED, BOLD],
+      COMMENT:            [BLUE, BOLD],
+      EMBDOC_BEGIN:       [BLUE, BOLD],
+      EMBDOC_LINE:        [BLUE, BOLD],
+      EMBDOC_END:         [BLUE, BOLD],
+      CONSTANT:           [BLUE, BOLD, UNDERLINE],
+      EMBEXPR_BEGIN:      [RED],
+      EMBEXPR_END:        [RED],
+      EMBVAR:             [RED],
+      FLOAT:              [MAGENTA, BOLD],
+      GLOBAL_VARIABLE:    [GREEN, BOLD],
+      HEREDOC_START:      [RED],
+      HEREDOC_END:        [RED],
+      FLOAT_IMAGINARY:    [BLUE, BOLD],
+      INTEGER_IMAGINARY:  [BLUE, BOLD],
+      FLOAT_RATIONAL_IMAGINARY:  [BLUE, BOLD],
+      INTEGER_RATIONAL_IMAGINARY:  [BLUE, BOLD],
+      INTEGER:            [BLUE, BOLD],
+      INTEGER_RATIONAL:   [BLUE, BOLD],
+      FLOAT_RATIONAL:     [BLUE, BOLD],
+      KEYWORD_END:        [GREEN],
+      KEYWORD_CLASS:      [GREEN],
+      KEYWORD_MODULE:     [GREEN],
+      KEYWORD_IF:         [GREEN],
+      KEYWORD_IF_MODIFIER: [GREEN],
+      KEYWORD_UNLESS_MODIFIER: [GREEN],
+      KEYWORD_WHILE_MODIFIER: [GREEN],
+      KEYWORD_UNTIL_MODIFIER: [GREEN],
+      KEYWORD_THEN:       [GREEN],
+      KEYWORD_UNLESS:     [GREEN],
+      KEYWORD_ELSE:       [GREEN],
+      KEYWORD_WHILE:      [GREEN],
+      KEYWORD_UNTIL:      [GREEN],
+      KEYWORD_CASE:       [GREEN],
+      KEYWORD_WHEN:       [GREEN],
+      KEYWORD_IN:         [GREEN],
+      KEYWORD_DEF:        [GREEN],
+      KEYWORD_DO:         [GREEN],
+      KEYWORD_DO_LOOP:    [GREEN],
+      KEYWORD_FOR:        [GREEN],
+      KEYWORD_BEGIN:      [GREEN],
+      KEYWORD_RESCUE:     [GREEN],
+      KEYWORD_ENSURE:     [GREEN],
+      KEYWORD_ALIAS:      [GREEN],
+      KEYWORD_UNDEF:      [GREEN],
+      KEYWORD_BEGIN_UPCASE: [GREEN],
+      KEYWORD_END_UPCASE: [GREEN],
+      KEYWORD_YIELD:      [GREEN],
+      KEYWORD_REDO:       [GREEN],
+      KEYWORD_RETRY:      [GREEN],
+      KEYWORD_NEXT:       [GREEN],
+      KEYWORD_BREAK:      [GREEN],
+      KEYWORD_SUPER:      [GREEN],
+      KEYWORD_RETURN:     [GREEN],
+      KEYWORD_DEFINED:    [GREEN],
+      KEYWORD_NOT:        [GREEN],
+      KEYWORD_AND:        [GREEN],
+      KEYWORD_OR:         [GREEN],
+      LABEL:              [MAGENTA],
+      LABEL_END:          [RED, BOLD],
+      PERCENT_UPPER_W:    [RED, BOLD],
+      PERCENT_LOWER_W:    [RED, BOLD],
+      PERCENT_LOWER_X:    [RED, BOLD],
+      REGEXP_BEGIN:       [RED, BOLD],
+      REGEXP_END:         [RED, BOLD],
+      STRING_BEGIN:       [RED, BOLD],
+      STRING_CONTENT:     [RED],
+      STRING_END:         [RED, BOLD],
+      __END__:            [GREEN],
+      # tokens from syntax tree traversal
+      method_name:        [BLUE, BOLD],
+      symbol:             [YELLOW],
+      # special colorization
+      error:              [RED, REVERSE],
+      const_env:          [CYAN, BOLD],
+    }.transform_values do |styles|
+      styles.map { |style| "\e[#{style}m" }.join
     end
-    private_constant :TOKEN_SEQ_EXPRS
-
-    ERROR_TOKENS = TOKEN_SEQ_EXPRS.keys.select { |k| k.to_s.end_with?('error') }
-    private_constant :ERROR_TOKENS
+    CLEAR_SEQ = "\e[#{CLEAR}m"
+    private_constant :TOKEN_SEQS, :CLEAR_SEQ
 
     class << self
       def colorable?
@@ -112,14 +144,13 @@ def inspect_colorable?(obj, seen: {}.compare_by_identity)
       end
 
       def clear(colorable: colorable?)
-        return '' unless colorable
-        "\e[#{CLEAR}m"
+        colorable ? CLEAR_SEQ : ''
       end
 
       def colorize(text, seq, colorable: colorable?)
         return text unless colorable
         seq = seq.map { |s| "\e[#{const_get(s)}m" }.join('')
-        "#{seq}#{text}#{clear(colorable: colorable)}"
+        "#{seq}#{text}#{CLEAR_SEQ}"
       end
 
       # If `complete` is false (code is incomplete), this does not warn compile_error.
@@ -128,135 +159,129 @@ def colorize(text, seq, colorable: colorable?)
       def colorize_code(code, complete: true, ignore_error: false, colorable: colorable?, local_variables: [])
         return code unless colorable
 
-        symbol_state = SymbolState.new
-        colored = +''
-        lvars_code = RubyLex.generate_local_variables_assign_code(local_variables)
-        code_with_lvars = lvars_code ? "#{lvars_code}\n#{code}" : code
+        result = Prism.parse_lex(code, scopes: [local_variables])
 
-        scan(code_with_lvars, allow_last_error: !complete) do |token, str, expr|
-          # handle uncolorable code
-          if token.nil?
-            colored << Reline::Unicode.escape_for_print(str)
-            next
-          end
+        # IRB::ColorPrinter skips colorizing syntax invalid fragments
+        return Reline::Unicode.escape_for_print(code) if ignore_error && !result.success?
+
+        errors = result.errors
+        unless complete
+          errors = errors.reject { |error| error.message =~ /\Aexpected a|unexpected end-of-input|unterminated/ }
+        end
+
+        prism_node, prism_tokens = result.value
+        visitor = ColorizeVisitor.new
+        prism_node.accept(visitor)
+
+        error_tokens = errors.map { |e| [e.location.start_line, e.location.start_column, 0, e.location.end_line, e.location.end_column, :error, e.location.slice] }
+        tokens = prism_tokens.map { |t,| [t.location.start_line, t.location.start_column, 2, t.location.end_line, t.location.end_column, t.type, t.value] }
+        tokens.pop if tokens.last&.[](5) == :EOF
 
-          # IRB::ColorPrinter skips colorizing fragments with any invalid token
-          if ignore_error && ERROR_TOKENS.include?(token)
-            return Reline::Unicode.escape_for_print(code)
+        colored = +''
+        line_index = 0
+        col = 0
+        lines = code.lines
+        flush = -> next_line_index, next_col {
+          return if next_line_index == line_index && next_col == col
+          (line_index...[next_line_index, lines.size].min).each do |ln|
+            colored << Reline::Unicode.escape_for_print(lines[line_index].byteslice(col..))
+            line_index = ln + 1
+            col = 0
+          end
+          unless col == next_col
+            colored << Reline::Unicode.escape_for_print(lines[next_line_index].byteslice(col..next_col - 1))
           end
+        }
+
+        (visitor.tokens + tokens + error_tokens).sort.each do |start_line, start_column, _priority, end_line, end_column, type, value|
+          next if start_line - 1 < line_index || (start_line - 1 == line_index && start_column < col)
 
-          in_symbol = symbol_state.scan_token(token)
-          str.each_line do |line|
-            line = Reline::Unicode.escape_for_print(line)
-            if seq = dispatch_seq(token, expr, line, in_symbol: in_symbol)
-              colored << seq.map { |s| "\e[#{s}m" }.join('')
-              colored << line.sub(/\Z/, clear(colorable: colorable))
-            else
-              colored << line
+          flush.call(start_line - 1, start_column)
+          if type == :CONSTANT && value == 'ENV'
+            color = TOKEN_SEQS[:const_env]
+          elsif type == :__END__
+            color = TOKEN_SEQS[type]
+            end_line = start_line
+            value = '__END__'
+            end_column = start_column + 7
+          else
+            color = TOKEN_SEQS[type]
+          end
+          if color
+            value.split(/(\n)/).each do |s|
+              colored << (s == "\n" ? s : "#{color}#{Reline::Unicode.escape_for_print(s)}#{CLEAR_SEQ}")
             end
+          else
+            colored << value
           end
+          line_index = end_line - 1
+          col = end_column
         end
-
-        if lvars_code
-          raise "#{lvars_code.dump} should have no \\n" if lvars_code.include?("\n")
-          colored.sub!(/\A.+\n/, '') # delete_prefix lvars_code with colors
-        end
+        flush.call lines.size, 0
         colored
       end
 
-      private
-
-      def without_circular_ref(obj, seen:, &block)
-        return false if seen.key?(obj)
-        seen[obj] = true
-        block.call
-      ensure
-        seen.delete(obj)
-      end
+      class ColorizeVisitor < Prism::Visitor
+        attr_reader :tokens
+        def initialize
+          @tokens = []
+        end
 
-      def scan(code, allow_last_error:)
-        verbose, $VERBOSE = $VERBOSE, nil
-        RubyLex.compile_with_errors_suppressed(code) do |inner_code, line_no|
-          lexer = Ripper::Lexer.new(inner_code, '(ripper)', line_no)
-          byte_pos = 0
-          line_positions = [0]
-          inner_code.lines.each do |line|
-            line_positions << line_positions.last + line.bytesize
+        def dispatch(location, type)
+          if location
+            @tokens << [location.start_line, location.start_column, 1, location.end_line, location.end_column, type, location.slice]
           end
+        end
 
-          on_scan = proc do |elem|
-            start_pos = line_positions[elem.pos[0] - 1] + elem.pos[1]
+        def visit_array_node(node)
+          if node.opening&.match?(/\A%[iI]/)
+            dispatch node.opening_loc, :symbol
+            dispatch node.closing_loc, :symbol
+          end
+          super
+        end
 
-            # yield uncolorable code
-            if byte_pos < start_pos
-              yield(nil, inner_code.byteslice(byte_pos...start_pos), nil)
-            end
+        def visit_def_node(node)
+          dispatch node.name_loc, :method_name
+          super
+        end
 
-            if byte_pos <= start_pos
-              str = elem.tok
-              yield(elem.event, str, elem.state)
-              byte_pos = start_pos + str.bytesize
+        def visit_interpolated_symbol_node(node)
+          dispatch node.opening_loc, :symbol
+          node.parts.each do |part|
+            case part
+            when Prism::StringNode
+              dispatch part.content_loc, :symbol
+            when Prism::EmbeddedStatementsNode
+              dispatch part.opening_loc, :symbol
+              dispatch part.closing_loc, :symbol
             end
           end
+          dispatch node.closing_loc, :symbol
+          super
+        end
 
-          lexer.scan.each do |elem|
-            next if allow_last_error and /meets end of file|unexpected end-of-input/ =~ elem.message
-            on_scan.call(elem)
+        def visit_symbol_node(node)
+          if (node.opening_loc.nil? && node.closing == ':') || node.closing&.match?(/\A['"]:\z/)
+            # Colorize { symbol: 1 } and { 'symbol': 1 } as label
+            dispatch node.location, :LABEL
+          else
+            dispatch node.opening_loc, :symbol
+            dispatch node.value_loc, :symbol
+            dispatch node.closing_loc, :symbol
           end
-          # yield uncolorable DATA section
-          yield(nil, inner_code.byteslice(byte_pos...inner_code.bytesize), nil) if byte_pos < inner_code.bytesize
         end
-      ensure
-        $VERBOSE = verbose
       end
 
-      def dispatch_seq(token, expr, str, in_symbol:)
-        if ERROR_TOKENS.include?(token)
-          TOKEN_SEQ_EXPRS[token][0]
-        elsif in_symbol
-          [YELLOW]
-        elsif TOKEN_KEYWORDS.fetch(token, []).include?(str)
-          [CYAN, BOLD]
-        elsif (seq, exprs = TOKEN_SEQ_EXPRS[token]; (expr & (exprs || 0)) != 0)
-          seq
-        else
-          nil
-        end
-      end
-    end
-
-    # A class to manage a state to know whether the current token is for Symbol or not.
-    class SymbolState
-      def initialize
-        # Push `true` to detect Symbol. `false` to increase the nest level for non-Symbol.
-        @stack = []
-      end
+      private
 
-      # Return true if the token is a part of Symbol.
-      def scan_token(token)
-        prev_state = @stack.last
-        case token
-        when :on_symbeg, :on_symbols_beg, :on_qsymbols_beg
-          @stack << true
-        when :on_ident, :on_op, :on_const, :on_ivar, :on_cvar, :on_gvar, :on_kw, :on_backtick
-          if @stack.last # Pop only when it's Symbol
-            @stack.pop
-            return prev_state
-          end
-        when :on_tstring_beg
-          @stack << false
-        when :on_embexpr_beg
-          @stack << false
-          return prev_state
-        when :on_tstring_end # :on_tstring_end may close Symbol
-          @stack.pop
-          return prev_state
-        when :on_embexpr_end
-          @stack.pop
-        end
-        @stack.last
+      def without_circular_ref(obj, seen:, &block)
+        return false if seen.key?(obj)
+        seen[obj] = true
+        block.call
+      ensure
+        seen.delete(obj)
       end
     end
-    private_constant :SymbolState
   end
 end
diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index 505bed80a..e1d363ec4 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -660,7 +660,7 @@ def colorize_input(input, complete:)
         lvars = local_variables || []
         if parse_command(input)
           name, sep, arg = input.split(/(\s+)/, 2)
-          arg = IRB::Color.colorize_code(arg, complete: complete, local_variables: lvars)
+          arg = IRB::Color.colorize_code(arg, complete: complete, local_variables: lvars) if arg
           "#{IRB::Color.colorize(name, [:BOLD])}\e[m#{sep}#{arg}"
         else
           IRB::Color.colorize_code(input, complete: complete, local_variables: lvars)
diff --git a/test/irb/test_color.rb b/test/irb/test_color.rb
index 9d78f5233..0b7fa83a7 100644
--- a/test/irb/test_color.rb
+++ b/test/irb/test_color.rb
@@ -77,9 +77,9 @@ def test_colorize_code
         "%w[a b]" => "#{RED}#{BOLD}%w[#{CLEAR}#{RED}a#{CLEAR} #{RED}b#{CLEAR}#{RED}#{BOLD}]#{CLEAR}",
         "%W[a b]" => "#{RED}#{BOLD}%W[#{CLEAR}#{RED}a#{CLEAR} #{RED}b#{CLEAR}#{RED}#{BOLD}]#{CLEAR}",
         "%s[a b]" => "#{YELLOW}%s[#{CLEAR}#{YELLOW}a b#{CLEAR}#{YELLOW}]#{CLEAR}",
-        "%i[c d]" => "#{YELLOW}%i[#{CLEAR}#{YELLOW}c#{CLEAR}#{YELLOW} #{CLEAR}#{YELLOW}d#{CLEAR}#{YELLOW}]#{CLEAR}",
-        "%I[c d]" => "#{YELLOW}%I[#{CLEAR}#{YELLOW}c#{CLEAR}#{YELLOW} #{CLEAR}#{YELLOW}d#{CLEAR}#{YELLOW}]#{CLEAR}",
-        "{'a': 1}" => "{#{RED}#{BOLD}'#{CLEAR}#{RED}a#{CLEAR}#{RED}#{BOLD}':#{CLEAR} #{BLUE}#{BOLD}1#{CLEAR}}",
+        "%i[c d]" => "#{YELLOW}%i[#{CLEAR}#{YELLOW}c#{CLEAR} #{YELLOW}d#{CLEAR}#{YELLOW}]#{CLEAR}",
+        "%I[c d]" => "#{YELLOW}%I[#{CLEAR}#{YELLOW}c#{CLEAR} #{YELLOW}d#{CLEAR}#{YELLOW}]#{CLEAR}",
+        "{'a': 1}" => "{#{MAGENTA}'a':#{CLEAR} #{BLUE}#{BOLD}1#{CLEAR}}",
         ":Struct" => "#{YELLOW}:#{CLEAR}#{YELLOW}Struct#{CLEAR}",
         '"#{}"' => "#{RED}#{BOLD}\"#{CLEAR}#{RED}\#{#{CLEAR}#{RED}}#{CLEAR}#{RED}#{BOLD}\"#{CLEAR}",
         ':"a#{}b"' => "#{YELLOW}:\"#{CLEAR}#{YELLOW}a#{CLEAR}#{YELLOW}\#{#{CLEAR}#{YELLOW}}#{CLEAR}#{YELLOW}b#{CLEAR}#{YELLOW}\"#{CLEAR}",
@@ -106,41 +106,16 @@ def test_colorize_code
         "foo\n__END__\nbar" => "foo\n#{GREEN}__END__#{CLEAR}\nbar",
         "foo\n<<A\0\0bar\nA\nbaz" => "foo\n#{RED}<<A#{CLEAR}^@^@bar\n#{RED}A#{CLEAR}\nbaz",
         "<<A+1\nA" => "#{RED}<<A#{CLEAR}+#{BLUE}#{BOLD}1#{CLEAR}\n#{RED}A#{CLEAR}",
-      }
-
-      tests.merge!({
         "4.5.6" => "#{MAGENTA}#{BOLD}4.5#{CLEAR}#{RED}#{REVERSE}.6#{CLEAR}",
-        "\e[0m\n" => "#{RED}#{REVERSE}^[#{CLEAR}[#{BLUE}#{BOLD}0#{CLEAR}#{RED}#{REVERSE}m#{CLEAR}\n",
+        "\e[0m\n" => "#{RED}#{REVERSE}^[#{CLEAR}[#{BLUE}#{BOLD}0#{CLEAR}m\n",
         "<<EOS\nhere\nEOS" => "#{RED}<<EOS#{CLEAR}\n#{RED}here#{CLEAR}\n#{RED}EOS#{CLEAR}",
-      })
-
-      # specific to Ruby 3.0+
-      if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.0.0')
-        tests.merge!({
-          "[1]]]\u0013" => "[#{BLUE}#{BOLD}1#{CLEAR}]#{RED}#{REVERSE}]#{CLEAR}#{RED}#{REVERSE}]#{CLEAR}#{RED}#{REVERSE}^S#{CLEAR}",
-        })
-        tests.merge!({
-          "def req(true) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}true#{CLEAR}) #{RED}#{REVERSE}end#{CLEAR}",
-          "nil = 1" => "#{RED}#{REVERSE}nil#{CLEAR} = #{BLUE}#{BOLD}1#{CLEAR}",
-          "alias $x $1" => "#{GREEN}alias#{CLEAR} #{GREEN}#{BOLD}$x#{CLEAR} #{RED}#{REVERSE}$1#{CLEAR}",
-          "class bad; end" => "#{GREEN}class#{CLEAR} #{RED}#{REVERSE}bad#{CLEAR}; #{GREEN}end#{CLEAR}",
-          "def req(@a) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}@a#{CLEAR}) #{GREEN}end#{CLEAR}",
-        })
-        if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.2.0')
-          tests.merge!({
-            "def req(true) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}true#{CLEAR}#{RED}#{REVERSE})#{CLEAR} #{RED}#{REVERSE}end#{CLEAR}",
-          })
-        end
-      else
-        tests.merge!({
-          "[1]]]\u0013" => "[#{BLUE}#{BOLD}1#{CLEAR}]#{RED}#{REVERSE}]#{CLEAR}]^S",
-          "def req(true) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}true#{CLEAR}) end",
-          "nil = 1" => "#{CYAN}#{BOLD}nil#{CLEAR} = #{BLUE}#{BOLD}1#{CLEAR}",
-          "alias $x $1" => "#{GREEN}alias#{CLEAR} #{GREEN}#{BOLD}$x#{CLEAR} $1",
-          "class bad; end" => "#{GREEN}class#{CLEAR} bad; #{GREEN}end#{CLEAR}",
-          "def req(@a) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(@a) #{GREEN}end#{CLEAR}",
-        })
-      end
+        "[1]]]\u0013" => "[#{BLUE}#{BOLD}1#{CLEAR}]#{RED}#{REVERSE}]#{CLEAR}#{RED}#{REVERSE}]#{CLEAR}#{RED}#{REVERSE}^S#{CLEAR}",
+        "def req(true) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}true#{CLEAR}#{RED}#{REVERSE})#{CLEAR} #{GREEN}end#{CLEAR}",
+        "nil = 1" => "#{CYAN}#{BOLD}nil#{CLEAR} #{RED}#{REVERSE}=#{CLEAR} #{BLUE}#{BOLD}1#{CLEAR}",
+        "alias $x $1" => "#{GREEN}alias#{CLEAR} #{GREEN}#{BOLD}$x#{CLEAR} #{RED}#{REVERSE}$1#{CLEAR}",
+        "class bad; end" => "#{GREEN}class#{CLEAR} #{RED}#{REVERSE}bad#{CLEAR}; #{GREEN}end#{CLEAR}",
+        "def req(@a) end" => "#{GREEN}def#{CLEAR} #{BLUE}#{BOLD}req#{CLEAR}(#{RED}#{REVERSE}@a#{CLEAR}) #{GREEN}end#{CLEAR}",
+      }
 
       tests.each do |code, result|
         assert_equal_with_term(result, code, complete: true)
@@ -166,15 +141,15 @@ def test_colorize_code_with_local_variables
       result_with_lvars = "a /(b +#{BLUE}#{BOLD}1#{CLEAR})/i"
 
       assert_equal_with_term(result_without_lvars, code)
-      assert_equal_with_term(result_with_lvar, code, local_variables: ['a'])
-      assert_equal_with_term(result_with_lvars, code, local_variables: ['a', 'b'])
+      assert_equal_with_term(result_with_lvar, code, local_variables: [:a])
+      assert_equal_with_term(result_with_lvars, code, local_variables: [:a, :b])
     end
 
     def test_colorize_code_complete_true
       # `complete: true` behaviors. Warn end-of-file.
       {
-        "'foo' + 'bar" => "#{RED}#{BOLD}'#{CLEAR}#{RED}foo#{CLEAR}#{RED}#{BOLD}'#{CLEAR} + #{RED}#{BOLD}'#{CLEAR}#{RED}#{REVERSE}bar#{CLEAR}",
-        "('foo" => "(#{RED}#{BOLD}'#{CLEAR}#{RED}#{REVERSE}foo#{CLEAR}",
+        "'foo' + 'bar" => "#{RED}#{BOLD}'#{CLEAR}#{RED}foo#{CLEAR}#{RED}#{BOLD}'#{CLEAR} + #{RED}#{REVERSE}'#{CLEAR}#{RED}bar#{CLEAR}",
+        "('foo" => "(#{RED}#{REVERSE}'#{CLEAR}#{RED}foo#{CLEAR}",
       }.each do |code, result|
         assert_equal_with_term(result, code, complete: true)