Tone – Created by adding pure grey to a colour
A different tone of a colour can be created by adding pure grey (a fifty-fifty mix of black and white) to a colour.
Note: Adding grey to a colour, no matter how light or dark, will tone down the intensity of a colour and could make it seem dull.
To remember that tones are colours with grey added, recall the following mnemonic:
She used a gentle tone to calm the big grey elephant down as it was charging her.
TONE = ADD GREY
Tones can have varying effects in paintings but tend to make things a little more dulled down and realistic. Edgar Degas' painting L'Absinthe is a prime example of tones being used to full effect. You can see that almost every colour appears to be a variant of grey, or a greyed-down tone rather than a bright vivid colour fresh from a tube.
Edgar Degas, L'Absinthe, 1875-76
Some artists create charts of their key colours to see how their tube paints will mix with grey and use these as a permanent reference
For example, a tone chart based on a cobalt blue paint from the tube would appear like this: