omnibox highlight too bright when using darker profile themes

[kjozwiak]

Description

On my current Nightly installation which is my daily driver with ~4 profiles, the ones using the darker theme are now using a really light omnibox separator which makes it really difficult to read what is being highlighted/selected as per the screenshot.

Steps to reproduce

I'm not 100% sure on the STR/Cases as I couldn't really reproduce the issue on a clean install, but after I updated my Nightly installation from C128 --> C129, noticed that the selector via the omnibox was too bright within my profiles using darker themes.

Regarding QA/Verification, I would run through the following:

• install a build that has the fix and ensure that the omnibox separator isn't too bright and items that are highlighted are legible
• have several profiles setup via C128 that use dark themes and upgrade to C129 and ensure the issue doesn't occur

Actual result

The current omnibox selector is really light which makes it really difficult to read which item is being selected as per the following:

Expected result

Should be a lot easier to read similar to the following:

Reproduces how often

Easily reproduced

Brave version (brave://version info)

Brave | 1.72.3 Chromium: 129.0.6668.42 (Official Build) nightly (64-bit)
-- | --
Revision | 86ff9ad73e0c9846e1cb572d6076c5f94a433268
OS | Windows 11 Version 23H2 (Build 22631.4112)

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

No response

[fallaciousreasoning]

*Note: To repro, install a custom dark theme from the Chrome web store (i.e. https://chromewebstore.google.com/detail/just-black/aghfnjkcakhmadgdomlmlhhaocbkloab)

[kjozwiak]

The above requires 1.71.91 or higher for 1.71.x verification 👍