I don't know if any pigment ink pad would work or only Colorbox. Why don't you try it out? You just dip you not-too-wet brush into the ink pad and paint onto watercolor paper. And remember even almost dry ink pads work. See, that's why I didn't throw those Petal Points out. I knew that someone would come up with a way to use them!
I am entering this card in the Simon Says Wednesday Challenge "Anything goes" which closes soon.
Thanks for your visit!