Insufficient contrast for sidebar labels and icons (accessibility)

Description:
Several text labels and icons in the app UI have very low color contrast against the background in their resting state, becoming clearly visible only on mouse hover.

A concrete example: the sidebar section labels (e.g. "Pinned", "System", "Ungrouped" in the Italian UI: "Fissato", "Sistema", "Non raggruppato") are nearly invisible until hovered, when they lighten slightly. The same pattern affects several other icons elsewhere in the interface.

For users with low vision, this makes these elements effectively unreadable/invisible during normal use, which is an accessibility barrier.

Suggested fix:
Instead of dimming/muting these elements in their resting state, use a different but clearly visible color that does not rely on hover to become legible