This CL use the introduce color variables
to adapt light theme feature to increase
accessibility.

Bug: v8:10644

Change-Id: I179831aef384527b0457c6ae93fa4d42a1814834
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2305891
Commit-Queue: Zeynep Cankara <zcankara@google.com>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69093}