[NTP][Enterprise] Set focus color

Screenshots:
http://screenshot/7LYyFjuyuQQwWE9
http://screenshot/3CmyKUvWCzfa7pt

Bug: 346375874
Change-Id: I8dc773af5e67c3aefcf761d306f8b64132209475
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5617472


Commit-Queue: Riley Tatum <rtatum@google.com>
Reviewed-by: Paul Adedeji <pauladedeji@google.com>
Cr-Commit-Position: refs/heads/main@{#1313133}