I've been trying to replicate the results of diode lasers on painted canvas but can't seem to find the right settings for the Xtool P2. Is it possible to get good results on painted canvas with this machine?

I've gotten interesting results with black and white but only because burning through the top layer to the canvas looks similar and interesting. However, when I try to get results that don't take advantage of the white canvas underneath I either get discoloration or muddy colors. 

Example photo, 2 layers of white, 3 layers of gold, and 1 layer of black. The gold gets discolored or muddy as seen in the photo or burned through entirely. 

The air assist is set to 30% for all of them except the ones framed by that square turned it to 100% to see if it helped.