Background customization in PTQ (according to the instrument class)

Hello Dear Fogwall: I was just wondering if it's possible to customize ptq in the sense, for example, of the graphic background for any given instruments. Of course, in the case of the Wurly and Rhody the colors ARE part of the package, but when one changes from the C3 to the M3 or to a Hapsichord, I think it would be nice to reflect such, at least minimally, by changing the graphics a little bit... perhaps some old looking fonts whenever the user uses a hapsichord (or even a hapsichord picture! )

Im not sure how the community will percieve this suggestion/question,  but if it's possible, I really would like to know.

Thanks as always!