What is Colour Bias or Base Colour?
You may have noticed that when colour comes straight from the tube in oils, or other paints, that they may have a ‘look’ that may tell you what colour they have as a base. By this I mean that some blues for example may have a red base, others may have a green base, so they will naturally complement other colours with a similar base colour. A green based blue will sit nicely next to another green based colour if you want your painting to have colours that all work together and ‘relate’ to each other.
When mixing colours it is important to remember what colour base each one has so that you have a better idea of how the resultant colour will look. If you want to avoid a dull greyed off result, this is especially important. Also if you mix more than two colours together, then add white to lighten the tone, mixing the wrong colours will end up with a ‘muddy’ result.
Some effective experiments are to try mixing red based colours like Cadmium Red with Ultramarine Blue (remember that there are different Ultramarines available), you will get a brownish mix when white is added. Then try mixing Lemon Yellow with Prussian Blue as they have a green base, then a little white to lighten the tone.
As you experiment with your colours you will gradually learn that each colour fromthe tube, especially in oils, has a base colour that can be exploited. If you are a tonal painter, learning to control your colour mixes will help in creating beautiful tonal effects, and a huge variety of ‘greys’.
For more information about colour bias or base, look at the short video from Winsor & Newton at the following link, and happy painting.