Media: Improve inactive view switcher link contrast

[nikvalani96]

This PR changes the inactive Media Library view switcher icon color from #c3c4c7 to #757575.

The updated color increases the contrast ratio against the white background from 1.74:1 to approximately 4.61:1, making the inactive but functional view switcher easier to identify.

Trac ticket: https://core.trac.wordpress.org/ticket/66081

Testing instructions

1. Navigate to Media → Library.
2. Switch between List and Grid views.
3. Verify that the inactive view switcher icon uses #757575.
4. Verify that the current, hover, and keyboard focus states continue to work correctly.

Checks performed

• npm run grunt -- precommit:css
• npm run build:dev

Both commands completed successfully.

Use of AI Tools

AI assistance: Yes
Tool(s): ChatGPT Codex
Model(s): GPT-5
Used for: Identifying the relevant CSS selector and providing testing and contribution workflow guidance. The final change and command results were reviewed by me.

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Test this pull request with WordPress Playground.

[nikvalani96]

Tested this PR using WordPress Playground.

I switched between the List and Grid views in Media Library and verified that the inactive view-switcher icon now uses #757575. The updated icon has improved contrast and the view switching continues to work correctly.

The change works as expected. Screenshot attached.

[adamsilverstein]

Looks good!