Remove $legacy from govuk-colour

govuk-frontend v5 deprecates the `$legacy` param in the `govuk-colour`
mixin. Continuing to use it produces warnings for each instance of it
in the CSS. It can be safely removed as alphagov/govuk-frontend#3576
notes that `it is non-operational and the parameter is only maintained to
prevent compilation errors`.

app/assets/stylesheets/component_guide/application.scss

@@ -270,7 +270,7 @@ html {
 // Rouge syntax highlighting
 // Based on https://github.com/alphagov/tech-docs-template/blob/master/template/source/stylesheets/palette/_syntax-highlighting.scss
 
-$code-00: scale-color(govuk-colour("light-grey", $legacy: "grey-4"), $lightness: 50%); // Default Background
+$code-00: scale-color(govuk-colour("light-grey"), $lightness: 50%); // Default Background
 $code-01: #f5f5f5; // Lighter Background (Unused)
 $code-02: #bfc1c3; // Selection Background
 $code-03: darken($govuk-secondary-text-colour, 2%); // Comments, Invisibles, Line Highlighting

app/assets/stylesheets/govuk_publishing_components/components/_attachment.scss

@@ -7,7 +7,7 @@ $thumbnail-background: govuk-colour("white");
 $thumbnail-border-colour: rgba(11, 12, 12, .1);
 $thumbnail-shadow-colour: rgba(11, 12, 12, .4);
 $thumbnail-shadow-width: 0 2px 2px;
-$thumbnail-icon-border-colour: govuk-colour("mid-grey", $legacy: "grey-3");
+$thumbnail-icon-border-colour: govuk-colour("mid-grey");
 
 .gem-c-attachment {
   @include govuk-font(19);

app/assets/stylesheets/govuk_publishing_components/components/_checkboxes.scss

@@ -6,7 +6,7 @@
   box-sizing: border-box;
   border-left-style: solid;
   border-left-width: 4px;
-  border-color: govuk-colour("mid-grey", $legacy: "grey-2");
+  border-color: govuk-colour("mid-grey");
   margin-top: govuk-spacing(2);
   margin-bottom: govuk-spacing(2);
   padding: govuk-spacing(2) govuk-spacing(4);

app/assets/stylesheets/govuk_publishing_components/components/_contextual-sidebar.scss

@@ -27,7 +27,7 @@
 .gem-c-contextual-sidebar__cta {
   border-top: 2px solid $govuk-brand-colour;
   margin-bottom: govuk-spacing(6);
-  background-color: govuk-colour("light-grey", $legacy: "grey-4");
+  background-color: govuk-colour("light-grey");
   display: block;
   padding: 0 govuk-spacing(3) govuk-spacing(3);
   text-decoration: none;

app/assets/stylesheets/govuk_publishing_components/components/_document-list.scss

@@ -53,7 +53,7 @@
 }
 
 .gem-c-document-list__item-context {
-  color: govuk-colour("dark-grey", $legacy: "grey-1");
+  color: govuk-colour("dark-grey");
 }
 
 .gem-c-document-list__item-description {
@@ -93,7 +93,7 @@
 }
 
 .gem-c-document-list__item--highlight {
-  border: 1px solid govuk-colour("mid-grey", $legacy: "grey-2");
+  border: 1px solid govuk-colour("mid-grey");
   padding: govuk-spacing(6);
   margin-bottom: govuk-spacing(6);
 

app/assets/stylesheets/govuk_publishing_components/components/_govspeak-html-publication.scss

@@ -77,7 +77,7 @@
       // and make all of thead and tfoot stand out
       thead,
       tfoot {
-        background-color: govuk-colour("light-grey", $legacy: "grey-3");
+        background-color: govuk-colour("light-grey");
       }
 
       thead th,
@@ -122,7 +122,7 @@
       // total and subtotal rows
       tr.subtotal > *,
       tr.total > * {
-        border-top: 3px solid govuk-colour("mid-grey", $legacy: "grey-2");
+        border-top: 3px solid govuk-colour("mid-grey");
       }
 
       tr.total > *,
@@ -133,7 +133,7 @@
       // the total is usually in the tfoot, so already has that background colour
       // but when it's used inside the tbody, it should also be highlighted
       tr.total {
-        background-color: govuk-colour("light-grey", $legacy: "grey-3");
+        background-color: govuk-colour("light-grey");
       }
     }
     // stylelint-enable selector-no-qualifying-type

app/assets/stylesheets/govuk_publishing_components/components/_image-card.scss

@@ -187,7 +187,7 @@
   font-size: 16px;
   font-size: govuk-px-to-rem(16px);
   margin: 0 0 calc(govuk-spacing(3) / 2);
-  color: govuk-colour("dark-grey", $legacy: "grey-1");
+  color: govuk-colour("dark-grey");
 
   @include govuk-media-query($from: tablet) {
     margin-bottom: 0;
@@ -213,7 +213,7 @@
   }
 
   .gem-c-image-card__list-item--text {
-    color: govuk-colour("dark-grey", $legacy: "grey-1");
+    color: govuk-colour("dark-grey");
   }
 
   .gem-c-image-card__list-item-link {

app/assets/stylesheets/govuk_publishing_components/components/_intervention.scss

@@ -4,7 +4,7 @@
   @include govuk-text-colour;
   @include govuk-responsive-padding(3);
   @include govuk-responsive-margin(6, "bottom");
-  background-color: govuk-colour("light-grey", $legacy: "grey-4");
+  background-color: govuk-colour("light-grey");
   border-left: 10px solid $govuk-success-colour;
 
   .govuk-body:last-of-type {

app/assets/stylesheets/govuk_publishing_components/components/_layout-header.scss

@@ -5,7 +5,7 @@
 @import "govuk/components/tag/tag";
 
 .gem-c-layout-header--production .govuk-header__container {
-  border-bottom-color: govuk-colour("red", $legacy: "bright-red");
+  border-bottom-color: govuk-colour("red");
 }
 
 .gem-c-layout-header--integration .govuk-header__container,
@@ -18,7 +18,7 @@
 }
 
 .gem-c-layout-header--development .govuk-header__container {
-  border-bottom-color: govuk-colour("dark-grey", $legacy: "grey-1");
+  border-bottom-color: govuk-colour("dark-grey");
 }
 
 .gem-c-layout-header--no-bottom-border,
@@ -124,15 +124,15 @@
 }
 
 .gem-c-environment-tag--production {
-  background-color: govuk-colour("red", $legacy: "bright-red");
+  background-color: govuk-colour("red");
 }
 
 .gem-c-environment-tag--example {
   background-color: govuk-colour("bright-purple");
 }
 
 .gem-c-environment-tag--development {
-  background-color: govuk-colour("dark-grey", $legacy: "grey-1");
+  background-color: govuk-colour("dark-grey");
 }
 
 .gem-c-environment-tag--staging,

app/assets/stylesheets/govuk_publishing_components/components/_related-navigation.scss

@@ -14,7 +14,7 @@
 
 .gem-c-related-navigation__sub-heading {
   @include govuk-font(16);
-  border-top: 1px solid govuk-colour("mid-grey", $legacy: "grey-2");
+  border-top: 1px solid govuk-colour("mid-grey");
   margin: 0;
   padding-top: govuk-spacing(3);
 }

app/assets/stylesheets/govuk_publishing_components/components/_step-by-step-nav-header.scss

@@ -6,7 +6,7 @@
 
   position: relative;
   padding: 10px;
-  background: govuk-colour("light-grey", $legacy: "grey-4");
+  background: govuk-colour("light-grey");
   border-bottom: solid 1px govuk-colour("blue");
   margin-top: govuk-spacing(3);
 

app/assets/stylesheets/govuk_publishing_components/components/_step-by-step-nav.scss

@@ -3,15 +3,15 @@
 $stroke-width: 1px;
 $number-circle-size: 30px;
 $number-circle-size-large: 35px;
-$top-border: solid 1px govuk-colour("mid-grey", $legacy: "grey-3");
+$top-border: solid 1px govuk-colour("mid-grey");
 
 @mixin step-nav-vertical-line($line-style: solid) {
   content: "";
   position: absolute;
   z-index: 2;
   width: 0;
   height: 100%;
-  border-left: $line-style $stroke-width govuk-colour("mid-grey", $legacy: "grey-2");
+  border-left: $line-style $stroke-width govuk-colour("mid-grey");
   background: govuk-colour("white");
 }
 
@@ -263,7 +263,7 @@ $top-border: solid 1px govuk-colour("mid-grey", $legacy: "grey-3");
     margin-left: calc($number-circle-size / 4);
     width: calc($number-circle-size / 2);
     height: 0;
-    border-bottom: solid $stroke-width govuk-colour("mid-grey", $legacy: "grey-2");
+    border-bottom: solid $stroke-width govuk-colour("mid-grey");
   }
 
   &::after {
@@ -322,7 +322,7 @@ $top-border: solid 1px govuk-colour("mid-grey", $legacy: "grey-3");
 
 .gem-c-step-nav__circle--number {
   @include step-nav-font(16, $weight: bold, $line-height: 29px);
-  border: solid $stroke-width govuk-colour("mid-grey", $legacy: "grey-2");
+  border: solid $stroke-width govuk-colour("mid-grey");
 
   .gem-c-step-nav--large & {
     @include step-nav-font(16, $tablet-size: 19, $weight: bold, $line-height: 29px, $tablet-line-height: 34px);
@@ -532,7 +532,7 @@ $top-border: solid 1px govuk-colour("mid-grey", $legacy: "grey-3");
 .gem-c-step-nav__context {
   display: inline-block;
   font-weight: normal;
-  color: govuk-colour("dark-grey", $legacy: "grey-1");
+  color: govuk-colour("dark-grey");
 
   &::before {
     content: " \2013\00a0"; // dash followed by  

app/assets/stylesheets/govuk_publishing_components/components/_subscription-links.scss

@@ -98,7 +98,7 @@
 .gem-c-subscription-links__feed-box {
   padding: govuk-spacing(3);
   margin-bottom: govuk-spacing(3);
-  background: govuk-colour("light-grey", $legacy: "grey-3");
+  background: govuk-colour("light-grey");
 
   .js-enabled &.js-hidden {
     display: none;

app/assets/stylesheets/govuk_publishing_components/components/_table.scss

@@ -2,15 +2,15 @@
 @import "govuk/components/table/table";
 
 $table-border-width: 1px;
-$table-border-colour: govuk-colour("mid-grey", $legacy: "grey-2");
+$table-border-colour: govuk-colour("mid-grey");
 $table-header-border-width: 2px;
-$table-header-background-colour: govuk-colour("light-grey", $legacy: "grey-3");
+$table-header-background-colour: govuk-colour("light-grey");
 $sort-link-active-colour: govuk-colour("white");
 $sort-link-arrow-size: 14px;
 $sort-link-arrow-size-small: 8px;
 $sort-link-arrow-spacing: calc($sort-link-arrow-size / 2);
 $table-row-hover-background-colour: rgba(43, 140, 196, .2);
-$table-row-even-background-colour: govuk-colour("light-grey", $legacy: "grey-4");
+$table-row-even-background-colour: govuk-colour("light-grey");
 
 .govuk-table__cell:empty,
 .govuk-table__cell--empty {

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_advisory.scss

@@ -25,7 +25,7 @@ $high-alert-border: #cc0000;
     }
 
     &.high-alert {
-      background-color: govuk-colour("light-grey", $legacy: "grey-3");
+      background-color: govuk-colour("light-grey");
       border: 1px solid $high-alert-border;
     }
 

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_attachment.scss

@@ -49,8 +49,8 @@
       }
 
       svg {
-        fill: govuk-colour("mid-grey", $legacy: "grey-3");
-        stroke: govuk-colour("mid-grey", $legacy: "grey-3");
+        fill: govuk-colour("mid-grey");
+        stroke: govuk-colour("mid-grey");
       }
     }
 

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_call-to-action.scss

@@ -10,7 +10,7 @@
 .gem-c-govspeak {
   .call-to-action {
     margin: 2em 0;
-    background-color: govuk-colour("light-grey", $legacy: "grey-3");
+    background-color: govuk-colour("light-grey");
     padding: 2em;
 
     &:first-child {

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_contact.scss

@@ -12,7 +12,7 @@
   // .address is used by the `$A` markdown pattern
   .address,
   .contact {
-    border-left: 1px solid govuk-colour("mid-grey", $legacy: "grey-2");
+    border-left: 1px solid govuk-colour("mid-grey");
     padding-left: govuk-spacing(3);
     margin-bottom: govuk-spacing(6);
     margin-top: govuk-spacing(6);

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_example.scss

@@ -8,7 +8,7 @@
 .govspeak, // Legacy class name that's still used in some content items - needs to be kept until `.govspeak` is removed from the content items.
 .gem-c-govspeak {
   .example {
-    border-left: 10px solid govuk-colour("mid-grey", $legacy: "grey-3");
+    border-left: 10px solid govuk-colour("mid-grey");
     padding: 1em 0 1em 1em;
     margin: 2em 0;
 

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_footnotes.scss

@@ -14,7 +14,7 @@
 .govspeak, // Legacy class name that's still used in some content items - needs to be kept until `.govspeak` is removed from the content items.
 .gem-c-govspeak {
   .footnotes {
-    border-top: 1px solid govuk-colour("mid-grey", $legacy: "grey-2");
+    border-top: 1px solid govuk-colour("mid-grey");
     margin-top: govuk-spacing(6);
     padding-top: govuk-spacing(2);
 

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_information-callout.scss

@@ -9,7 +9,7 @@
 .govspeak, // Legacy class name that's still used in some content items - needs to be kept until `.govspeak` is removed from the content items.
 .gem-c-govspeak {
   .info-notice {
-    border-left: 10px solid govuk-colour("mid-grey", $legacy: "grey-3");
+    border-left: 10px solid govuk-colour("mid-grey");
     padding: 1em 0 1em 1em;
     margin: 2em 0;
 

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_place.scss

@@ -3,7 +3,7 @@
 .gem-c-govspeak {
   .place {
     margin: 1.5em 0;
-    border-bottom: solid 1px govuk-colour("mid-grey", $legacy: "grey-2");
+    border-bottom: solid 1px govuk-colour("mid-grey");
     padding-bottom: 1.5em;
 
     .address {

app/assets/stylesheets/govuk_publishing_components/components/govspeak/_tables.scss

@@ -25,7 +25,7 @@
     td {
       vertical-align: top;
       padding: govuk-spacing(2) govuk-spacing(4) govuk-spacing(2) 0;
-      border-bottom: 1px solid govuk-colour("mid-grey", $legacy: "grey-2");
+      border-bottom: 1px solid govuk-colour("mid-grey");
 
       &:last-child {
         padding: govuk-spacing(2) 0 govuk-spacing(2) 0;

app/assets/stylesheets/govuk_publishing_components/govuk_frontend_support.scss

@@ -11,9 +11,9 @@
 $gem-secondary-button-colour: #00823b;
 $gem-secondary-button-hover-colour: darken($gem-secondary-button-colour, 5%);
 $gem-secondary-button-background-colour: govuk-colour("white");
-$gem-secondary-button-hover-background-colour: govuk-colour("light-grey", $legacy: "grey-4");
+$gem-secondary-button-hover-background-colour: govuk-colour("light-grey");
 
-$gem-quiet-button-colour: govuk-colour("dark-grey", $legacy: "grey-1");
+$gem-quiet-button-colour: govuk-colour("dark-grey");
 $gem-quiet-button-hover-colour: darken($gem-quiet-button-colour, 5%);
 
 $gem-hover-dark-background: #dddcdb;