Ticket #55989: #55989.patch

wp-content/themes/twentytwentyone/assets/sass/05-blocks/quote/_editor.scss

@@ -23 +23 @@
         }
 
         .wp-block-quote__citation {
-                color: var(--global--color-primary);
+                color: currentColor;
                 font-size: var(--global--font-size-xs);
                 font-style: var(--quote--font-style-cite);
 
@@ -147 +147 @@
                         margin-right: auto;
                 }
         }
-}
+}
+ No newline at end of file