Attempt to improve color documentation

optex/base/colors.opm

@@ -320,30 +320,26 @@ PDF.
 
 \TeX/ itself has no concept of colors. Colors have always been handled by
 inserting whatsits (either using `\special` for DVI or using
-`\pdfliteral`/`\pdfcolorstack` for PDF). It is very efficient way of doing
-it, \TeX/ doesn't have to know anything about colors, it just inserts the
-relevant literals when doing `\shipout`. However, it is also problematic in
-many ways.
-
-This is reason we decide to change colors handling from `\pdfcolorstack` to
-\LuaTeX/ attributes in version 1.04 of \OpTeX. Using attributes, the color
-setting looks exacly like font selection from \TeX/ point of view: it
-respects \TeX/ groups, colors can span to more pages, independent colors
-can be set for in all `\insert`s. Moreover, once a material is typeset
-(using `\setbox` for example) then it has its fonts and its colors
-definitelly set and you can rely on it when you are using `\unhbox` etc.\
-operations. There are no internal whatsits for colors which can interferre
-with other typesetting material.
-
-The \LuaTeX/ attributes can be set like other register settings and after
-such a setting, their values are bound to essentially everything \TeX/ creates
-(characters, rules, glues, \dots).
-We use one attribute \^`\_colorattr` for information of currently selected
-color. Setting a color means only to set appropriate value to this attribute.
-The value is propagated to each created typesetting element until the attribute
-is unset or set to another value. So, setting the attribute behaves exactly
-like selecting the font. You can use `{\bf text}` to have text in bold and
-`{\Red text}` to have text in red.
+`\pdfliteral`/`\pdfcolorstack` for PDF). It is very efficient and \TeX/ doesn't
+even have to know anything about colors, but it is also problematic in many
+ways.
+
+That is the reason why we decided to change color handling from
+`\pdfcolorstack` to \LuaTeX/ attributes in version 1.04 of \OpTeX. Using
+attributes, the color setting behaves exactly like font selection from \TeX/
+point of view: it respects \TeX/ groups, colors can span more pages,
+independent colors can be set for `\insert`s, etc. Moreover, once a material is
+created (using `\setbox` for example) then it has its fonts and its colors
+frozen and you can rely on it when you are using e.g. `\unhbox`. There are no
+internal whatsits for colors which can interfere with other typesetting
+material. In the end something like setting text to red (`{\Red text}`) should
+have the same nice behavior like setting text to bold (`{\bf text}`).
+
+\LuaTeX/ attributes can be set like count register -- one attribute holds one
+number at a time. But the value of attribute is propagated to each created
+typesetting element until the attribute is unset or set to another value. Very
+much like the font property. We use one attribute \^`\_colorattr` for storing
+the currently selected color (in number form).
 
 Macros \^`\setcmykcolor``{<C> <M> <Y> <K>}` or \^`\setrgbcolor``{<R> <G> <B>}`
 or\nl \^`\setgreycolor``{<Grey>}` are used in color selectors. These

optex/doc/optex-userdoc.tex

@@ -1413,18 +1413,18 @@
    \setbox0=\hbox{#2#3}\leavevmode
    \rlap{#1\strut \vrule width\wd0}\box0
 }
-The following example defines the macro for the
-\coloron\Yellow\Brown{colored text on the colored background}. Usage:
+The following example defines the macro for
+\coloron\Yellow\Brown{colored text on colored background}. Usage:
 `\coloron<background><foreground>{<text>}`
 
-The `\coloron` can be defined as follows:
+The `\coloron` macro can be defined as follows:
 
 \begtt
 \def\coloron#1#2#3{%
    \setbox0=\hbox{#2#3}%
    \leavevmode \rlap{#1\strut \vrule width\wd0}\box0
 }
-\coloron\Yellow\Brown{The brown text on the yellow background}
+\coloron\Yellow\Brown{Brown text on yellow background}
 \endtt
 
 \secc Images