Fix help block <a> to meet colour contrast guidelines

- Fixes #9569

CHANGELOG.txt

@@ -25,6 +25,7 @@ Changelog
  * Fix: Text within status tags text will now resize correctly when customizing browser font size (Mary Ojo)
  * Fix: Ensure logo shows correctly on log in page in Windows high-contrast mode (Loveth Omokaro)
  * Fix: Comments notice background overflows its container (Yekasumah)
+ * Fix: Ensure links within help blocks meet colour contrast guidelines for accessibility (Theresa Okoro)
 
 
 4.1.1 (xx.xx.xxxx) - IN DEVELOPMENT

CONTRIBUTORS.rst

@@ -659,6 +659,7 @@ Contributors
 * Jordan Rob
 * Juliet Adeboye
 * Yekasumah
+* Theresa Okoro
 
 Translators
 ===========

client/scss/components/_help-block.scss

@@ -16,7 +16,7 @@
   }
 
   a {
-    color: theme('colors.secondary.DEFAULT');
+    color: theme('colors.secondary.400');
     text-decoration: underline;
     text-decoration-thickness: 2px;
     text-underline-offset: 3px;

docs/releases/4.2.md

@@ -36,6 +36,7 @@ depth: 1
  * Incorrectly formatted link in the documentation for Wagtail community support (Bolarinwa Comfort Ajayi)
  * Ensure logo shows correctly on log in page in Windows high-contrast mode (Loveth Omokaro)
  * Comments notice background overflows its container (Yekasumah)
+ * Ensure links within help blocks meet colour contrast guidelines for accessibility (Theresa Okoro)
 
 ## Upgrade considerations