1. to change or spoil the color of something; to make something lose its original color
Usage: British spelling; American spelling is 'discolor'; transitive verb

Examples

• The wine discoloured the white tablecloth.
• Rust will discolour the metal if left untreated.
• Years of sun exposure discoloured the old photograph.
• Coffee can discolour your teeth over time.
• The fabric discoloured after washing in hot water.