I recently had another artist bemoan the fact that she had great difficulty in mixing colours correctly and was taking far too much of her precious time to achieve the desired result. I felt her greatest drawback was the vast array of colours she had accumulated and thus it had become a bit of a monster for her. The more she tried, the more trouble she had and so she would buy another tube of paint to try again! My suggestion was to simplify and begin with just three primaries, in this case it was Ultramarine Blue, Cad. Yellow Pale and Alizarin to mix and keep mixing (with White too) and see the huge range of beautiful colours that come of this combination, all the greens, greys, violets, umbers are endless. The advantage with a limited palette is harmony in the painting. Once you are familiar with what the primaries can do when mixed together, then other colours can be added as need be. Happily I can say she is very pleased with the results so far and is becoming far more confident in her colour mixing. This painting "Magpie's Rest" was painted only from the three primary colours mentioned above and the result is a vibrant and harmonious painting.