The Vein Test
Knowing your skin tone is a good way of working out which colours suit you, it also makes you look differently at which model you will choose to work with. Different skin tones (not types) are classed as Warm / Cool / Neutral.
The simplest test you can do is look at the colour of your veins, or the models veins that you are casting.
Green coloured veins - Warm tones
Blue coloured veins - Cool tones
Blue/green or even purple veins - Neutral tones
How does knowing if you are Warm / Cool or Neutral help you?
Warm - clear light colours
Cool - dark colours
Neutral, you can wear any colour.