Lesson on Mixing colours: There are 8 colours we put out when we paint a picture unless we are doing a specific technique. They are Two reds (a cool and a warm), two yellows ( a cool and a warm), two blues ( a cool and a warm), purple and a white. From these colours we can make: Yellow and red make orange, Yellow and Blue make green, Red and blue make purple. The complimentary colours are: Yellow and purple, Red and Green, Blue and orange. When you want to tone down a colour you add a complimentary colour eg. if something is purple you add a little yellow to tone it down. Same with the other complimentary colours.(if something is too red, add green) etc. To make a neutral grey, mix three primary colours together in equal amounts.. eg. ultramarine blue +alizarin crimson + Cadmium yellow. If your mix has too much yellow in it, add more alizarin crimson + Ultramarine Blue, if it is too red add yellow and blue. etc.