Fix list group action item color

Author: mturac

scss/_variables.scss

@@ -1600,7 +1600,7 @@ $list-group-active-border-color:    $list-group-active-bg !default;
 $list-group-disabled-color:         var(--#{$prefix}secondary-color) !default;
 $list-group-disabled-bg:            $list-group-bg !default;
 
-$list-group-action-color:           var(--#{$prefix}secondary-color) !default;
+$list-group-action-color:           var(--#{$prefix}list-group-color) !default;
 $list-group-action-hover-color:     var(--#{$prefix}emphasis-color) !default;
 
 $list-group-action-active-color:    var(--#{$prefix}body-color) !default;

scss/tests/components/_list-group.test.scss

@@ -0,0 +1,19 @@
+@import "../../functions";
+@import "../../variables";
+
+@include describe("list group variables") {
+  @include it("uses the regular item color for action items") {
+    @include assert-equal(
+      $list-group-action-color,
+      var(--#{$prefix}list-group-color),
+      "Action items should inherit the regular list group item color"
+    );
+  }
+
+  @include it("keeps action items visually distinct from disabled items") {
+    @include assert-true(
+      $list-group-action-color != $list-group-disabled-color,
+      "Action items should not use the disabled list group color"
+    );
+  }
+}