The best advice I can give you is use a different chip for NCV's than you use for $ chips.
Example: If you use Chipco's for $ chips, use BJ or PS for the NCV's and do not have inserts in the NCV's.
BJ and PS both have "Hot" colors that make good NCV's. They are pretty easy to spot in a stack of chips.
Have them send you samples and mix them with your $ chips to see how they stand out.