1st Physical key - the essence of color , color spectrum 2nd Physical key - color circle , color distributions 3rd Physical key - additive aggregation colors , RGB 4th Physiological key - color vision 5th Physiological key - Optical properties of colors 6th Physiological key - chord color , color harmony 7th Physiological key - color composition of color in space 8th Chemical key - color as the material 9th Chemical key - the composition of colors, color schemes and swatches 10th Chemical key - subtractive census colors CMYK 11th Chemical key - the use of color in interior and exterior 12th Psychological key - color perception , color symbolism 13th Individual work - painting Still-life simple