mgr/dashboard: Improve dashboard usability for visually impaired users
Picking up suggestions raised in #35692 and #35691: we should add UI enhancements for users with vision impairments, e.g. creating a high-contrast theme or using patterns for users affected by color blindness.
These enhancements should not be specific to the landing page, but should apply to the entire dashboard, e.g. as a user-specific config setting.