crim·son 
(krĭmzən)
(krĭmzən)n.
A deep to vivid purplish red to vivid red.
tr. & intr.v. crim·soned, crim·son·ing, crim·sons
To make or become deeply or vividly red.
[Middle English cremesin, from Old Spanish cremesín, Old Italian cremesino or Medieval Latin cremesīnus, all from Arabic qirmizī, from qirmiz, kermes insect; see KERMES.]
crimson adj.