Rainbows and spectra

Black is usually used in addition to the three primaries to strengthen dark areas and add definition to the picture.

Use of subtractive primaries

Many everyday objects are coloured by printing, painting or dyeing and we see colour when light is reflected from their surfaces.

One of the most widespread uses of the subtractive primaries is in the printing of coloured newspapers, magazines and books. If you use a magnifying glass to look at the colour you can often see the tiny dots of magenta, cyan and yellow used. A red area would be made up of magenta and yellow dots.