improve invite tile color

[gabrc52]

Signed-off-by: Gabriel Rodríguez rgabriel@mit.edu

Fixes #26098

Checklist

• Tests written for new code (and old code if feasible)
• Linter and other CI checks pass
• Sign-off given on the changes (see CONTRIBUTING.md)

Notes: Fixes invite dialog pill color contrast

Before screenshots

See #26098

After screenshots

Dark theme (5.3 contrast ratio):

Light theme (3.5 contrast ratio):

Let us know if we should make a new variable (and how to name it!) or use an existing variable, or if you disagree with the color choice. There was no existing more specific alias for --cpd-color-blue-800: the closest was

--cpd-color-icon-info-primary: var(--cpd-color-blue-900);

but it does not seem to be enough contrast for dark theme.

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[github-actions]

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