spectral color

NOUN /spɛktrəl_'kələr/
14 LETTERS · STARTS WITH S

spectral color is a valid 14-letter word worth 19 points in Scrabble and 24 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
S1P3E1C3T1R1A1L1C3O1L1O1R1
1 + 3 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 =19 PTS
DOUBLE WORD → 38TRIPLE WORD → 57
MEANING

What does spectral color mean?