We Tone a colour by adding some of the contrasting colour to make a form of grey

Just before a colour becomes the perfect grey (with equal proportions of primary paint colours- red, blue, yellow) it will be a taupe. There is a slight predominance of a secondary colour (orange-taupe, green-taupe, purple-taupe)

Notice before dawn or after dusk that often the high chroma colour becomes muted. Nature often provides examples of interesting toned colours.

when you tone a colour it creates a calm feel. Even when it is contrasted with black or white, because it is closer to grey than a high chroma primary colour, there is less impact.

Meet Tony Tone!

He is a toned Orange (with green added to tone him down)

green tones

orange tones

purple tones

mix a contrasting colour to create a toned colour