Merge "Increase rainbow colors legibility" into udc-dev am: 14812d9934

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/23352499

Change-Id: I3a10a41d2812acbe2711d39fc06c40aeac8ddb87
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>