Strawberry tongue is a red discoloration of the tongue that may be caused by certain illnesses, such as scarlet fever. A bright red tongue that occurs with fever, sore throat, or other symptoms may be a sign of illness that requires medical attention.
Drinking colored drinks (such as Kool-Aid) or eating brightly colored candy may stain the tongue temporarily, giving it an alarming appearance. If this is the cause, the color will fade on its own or will go away with a thorough mouth cleaning.
WebMD Medical Reference from Healthwise