Okay so you are a color guru right. You are very comfortable with your full palette of 26 different paint colors and all that. Wonderful now want to learn to get even more comfortable with color then it is time to mix it up a bit. Try variations of a limited color palette with variations of red yellow and blue with mixed grays(to control intensity). This will strengthen your understanding of all the different colors your can get with just three colors with white and black as well of course. Then take it a bit further. Use like thalo blue, alizarin crimson and lemon yellow or any variant where you are really pushing the color mixtures to favor a warm or cool side. This will give you paintings a definite warm or cool painting which is always makes a painting stronger. You want all you painting to be consistent in structure, composition, approach and especially color. If you look at a painting and can’t define if the painting is warm or cool than the painting is weaker like the artist couldn’t make a definite decision. Using limited palettes with a warm or cool leaning will make up your mind for you.
Using the limited palettes will not only help you strengthen your color mixing and value skills you will more readily be able to control the overall temperature of your painting. Give it a try. Get out there and paint!