"paint" program to edit colors in styles?

[z0diac]

Does anyone know if there's a simple style editor mod that will let you just point to the part of a page you want to change the color to, then pick the color?

I'm finding it IMPOSSIBLE via trial and error - change a colour, try and go find what changed, to back, change something else, find out what that was, etc, etc,.....

Is there a mod out there (standalone program?) that will let you just point and click on the part of a certain page you want to change the colour for?