[ntp] Updates description text color

Selected: screenshot/9AS9mXP3vpegdhu
Not selected: screenshot/8jCbHEEUg4C2A28

Fixed: 1080876
Change-Id: Ie4263bf5fb9c1f6f27b8fe4ea6fae2741a113ec1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2583024Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: Andre Vincent <andrevincent@google.com>
Cr-Commit-Position: refs/heads/master@{#835913}

chrome/browser/resources/new_tab_page/customize_shortcuts.html

@@ -136,6 +136,10 @@
     color: var(--cr-secondary-text-color);
   }
 
+  .selected .option-description {
+    color: var(--ntp-selected-border-color);
+  }
+
   #hide {
     align-items: center;
     border: 1px solid var(--ntp-border-color);