You can technically do it using white but it would have to be the 2nd color as it would be the filler, though it would likely flatten the initial color a bit. I would suggest trying a 2 color marble effect and then hitting it with white as the filler. This would add some depth for sure.
Some techniques are actually discovered purely by accident so don't be scurrrred to try something different. Use crap pieces of lexan to test different things on.