- subtractive: "color you can touch" (e.g., skin of an apple)
- controlled by CMYK colorspace
- additive: "color you can't touch" (e.g., light from a computer screen)
- controlled by RBG colorspace
- best visualized as a colorwheel:
- hue is measured in degrees (red: 0º, green: 120º, blue: 240º)
- saturation goes from 0 to 100% where 0% is grey and 100% is as vivid as possible