primary colour for light

NOUN
24 LETTERS · STARTS WITH P

primary colour for light is a valid 24-letter word worth 37 points in Scrabble and 42 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3R1I1M3A1R1Y4C3O1L1O1U1R1F4O1R1L1I1G2H4T1
3 + 1 + 1 + 3 + 1 + 1 + 4 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 0 + 1 + 1 + 2 + 4 + 1 =37 PTS
DOUBLE WORD → 74TRIPLE WORD → 111
MEANING

What does primary colour for light mean?

NOUN · 1 SENSE
1

Any of three primary colors of light from which all colors can be obtained by additive mixing.