This adds a splash of color and some refinement to the revision slider

icons, helping make them stand out from nearby text and giving them a

blue-ish appearance indicating that they're interactive. The icons are

two pixels wider, giving them just a bit more of a hitbox.
The grey range indicator is now more of a grey-blue, helping it fit in

with the appearance while also not itself looking interactive or

clashing too much with the slider handles.

Tested on high-DPI and standard resolution screens.