Continuing this & some other relevant points in the thread Shonai_Dweller pointed out, paint & pigments in general merit being fleshed out a lot more--not only are all of our current dye sources organic (and therefore relatively non-dwarfy), but they're all from
imaginary plants that exist only in DF. Dwarves deserve to fully capitalize on pigments from more real-life mineral sources, in particular crushed gems and metal dust. Organically-sourced pigments (and other treatments, like shellac) could be traded for from non-dwarven civs, or produced by non-dwarven residents in your fort, or alternatively be a fully native industry, as your civ's randomized ethics and your access to the raw materials permit.
As for
what the dwarves can paint, I think we can assume that statues and engravings are a given. If dwarves shun the use of eggs and plant oils, and instead make plaster for the binder, suddenly we have frescoes. Paint can also be applied to shields and Shaped armor, though it would probably have to be re-applied every time the armor got hit, so it might be best when used for display purposes only. As for painting on non-dwarfy media like cloth, that can be another randomized ethical variation. Another possible random wrinkle is whether each society accepts depictions of things like geometric designs / plants / animals / people / people who have died / titans / gods / etc.
The mechanics should be pretty basic--just rename the Glazer profession to Painter, and give them their own Painter's Studio.
Functional pottery glazing to make an object waterproof would be performed by the Potter and contribute to that skill, while
decorative glazes would be added by a Painter.
Another fun little trick could be the ability to paint blocks, so you could build a big blue gate decorated with wild animals (the real one is actually not pained).
For me, reading that conjured up
another image altogether.
The problem more lies in the fact that it [painting] has no real practical use as of yet.
It would have exactly the same use that smoothing / engraving walls & floors, and decorating crafts & furniture, does currently.