Hi. This is a feature request, and I don't believe it can be done as a plugin, but maybe I'm wrong there.
In any event, I know that I would find it one of those "didn't know I needed it but now can't live without it" features.
First of all, this feature does need another feature to be added, which is the implementing of matching quote awareness (jEdit's "matching elements" color setting only works for brackets, not quotes as far as I can tell).
The idea is to make all matching operators -- quotes, brackets, etc. -- use (if activated) a cycling color palette, so that if, for example, I had a complex line of code with different brackets and sets of quotes, each matching pair would be easily seen because each pair would automatically have its own special color. There could be a default and configurable palette (of ... how many colors? 5? 10?) that could be used for this. This could be either text color or background color. Just to be sure I'm understood here: One pair of matching elements would have color 0 in the palette, another would have color 1 in the palette, another would have color 2, etc., until the end of the palette is reached and it cycles through the palette again.
I for one would find a 'cycling color pairs' (with configurable palette) setting for matching elements (including quotes) to be very cool. And I don't think I've seen this anywhere (although I have seen matching quote highlighting).