Turning into dull Colours

You know the dull sky and the dull emotion it gives. Similarly the dullness of colour evolves. The complementary of a pure primary colour is always made by the other two primary colours. So: green is made by blue and yellow and the complementary to red. Same with orange out of yellow and red being the complementary to blue, violet out of blue and red as the complementary to yellow. Mixing the paint of all primary colours red – yellow – blue together it turns into a dark grayish-brown something. The path towards that is turning pure into dull colours. One turns a colour into dull through its complementary, one takes away more and more brightness so that it ends in a shady type. Many colours of matter have at least a hue of dullness, since they are not light but just evolved through subtraction of light rays. So it’s a total natural fact, the question is, how much dullness do I artificially add around me if I also have the choice of pure vibrant colours.