Fix tint color in wpios

[kean]

At some point when introducing new colors, wpios was updated to use .brand instead of .primary, which is incorrect.

This PR fixes the primary tint color and also removes .brand entirely to avoid any confusion in the future. The new blue color also uses a slightly lighter shade in dark mode – just like we do in jpios. The previous town was too dark.

Before

After

To test:

Regression Notes

1. Potential unintended areas of impact

2. What I did to test those areas of impact (or what existing automated tests I relied on)

3. What automated tests I added (or what prevented me from doing so)

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Testing checklist:

• WordPress.com sites and self-hosted Jetpack sites.
• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• VoiceOver.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• iPhone and iPad.
• Multi-tasking: Split view and Slide over. (iPad)

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr23946-ff83911
	Version	25.6
	Bundle ID	org.wordpress.alpha
	Commit	ff83911
	App Center Build	WPiOS - One-Offs #11277

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr23946-ff83911
	Version	25.6
	Bundle ID	com.jetpack.alpha
	Commit	ff83911
	App Center Build	jetpack-installable-builds #10314

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.