Discolour , stain and tarnish all mean to change the colour of something for the worse. Discolour shares with stain the specific meaning of changing something to a different colour, stain emphasizing that this change is caused by foreign matter. Thus, after a fight, one’s clothes are likely to be discoloured , especially if they are stained with sweat, dirt and blood.

Discoloured shares with tarnish the specific meaning of depriving of colour, or of dulling. Discolour is used in this sense when fading, streaking or the like are referred to: curtains discoloured by the action of sunlight. Tarnish is used to refer to the dulling of lustre by action of air, dirt, water or the like: silverware tarnished by the action of sulphur compounds in the atmosphere and in such foods as eggs.