I am taking the easy way out with this. 1 picture says it all. From the Renaissance master, no less.
![[Image: whitesignage6nu.jpg]](http://img218.imageshack.us/img218/9682/whitesignage6nu.jpg)
WAH LIAO! Like that also can ah!!!!

In short, spray a white base before laying on your colours if you want to have vibrant, rich colours (eg yellow, orange, red).