You will end up with a rainbow of colors.
Platinum = steel blue back ground, cambodian, NR, maybe spread genes, metallic
Black dragon = Black, copper (steel blue back ground, metallic), dragon
Platinum x Black dragon = probabilities; cambodian like colors (partial dragon, metallic, and maybe regular), multi copper, multi turquoise, partial black dragon (probably with some red on it), multi platinum (not clean white color). . . . . kepp in mind that this is not definite. Results depends on their genetic background, which/whose genes are dominant/ stronger in the individual's line.