The colours which work best are close together on the colour wheel. Thus most of our combinations are segments of the rainbow. I don't currently use black, mostly because I don't like it on babies! I use two different reds, one is pinker and one is more orange. When the rest of the piece is veering towards blues and purples I use the fuchsia red, when it goes towards the yellow end of the spectrum I use the scarlet. In full rainbow pieces I can use either. I prefer the fuchsia but let me know what you would like. This list is not totally exhaustive; you may have a set of colours in mind which will work beautifully. Let me know, I'm flexible. I have found however that colours which, when mixed together go a bit muddy, for example yellow and purple, don't really work for me. Think of the pots of paint in kindergarten when you forgot to clean the brush, not so nice. With combinations where there are potential muds, e.g. the rainbow or mango options, more formal styles, which keep the colours from mingling too freely work best.