Contrast works fine, but you have to understand it.
There are two to 3 pigment consistencies. You will get 2-3 different results based on that.
the new glacier paint is a good example. it's designed to go over white and pre-highlights, to make it look like the object you are painting is ice.
It consequently has a lower pigmentation and you are not going to get good coverage over it.
Same thing with athermatic blue, which is more of a glaze.
Then you have the heavier pigmentations, like cygor brown.
finally, with some of the newer paints, they are really high coverage and pigmentation, but they are mostly opaque and that tends to make them come out with their own look.
Lets start with a saurus warrior.
What color scheme do you want to use? I can provide suggestions and use examples. - replies may be limited due to the holiday in the short term -.