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.