Function remap_frame_visuals 

pub fn remap_frame_visuals(
    visuals: &mut FrameVisuals,
    old_hover: Color32,
    new_hover: Color32,
    old_click: Color32,
    new_click: Color32,
    old_highlight: Color32,
    new_highlight: Color32,
)

Remap hover/click fills on FrameVisuals when they still match the previous palette.