Why is the British Empire coloured pink on maps?
The practice of colouring in the Empire in pink on maps and globes began in the 19th century.
Pink is actually a printer’s compromise, as the colour that is really associated with the British Empire is red.
However, a red background made it difficult to read letters overprinted in black, and so pink was used as a colour close to red but light enough for the lettering to be clearly legible.