primary subtractive colour for light

NOUN
36 LETTERS · STARTS WITH P

primary subtractive colour for light is a valid 36-letter word worth 55 points in Scrabble and 64 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3R1I1M3A1R1Y4S1U1B3T1R1A1C3T1I1V4E1C3O1L1O1U1R1F4O1R1L1I1G2H4T1
3 + 1 + 1 + 3 + 1 + 1 + 4 + 0 + 1 + 1 + 3 + 1 + 1 + 1 + 3 + 1 + 1 + 4 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 0 + 1 + 1 + 2 + 4 + 1 =55 PTS
DOUBLE WORD → 110TRIPLE WORD → 165
MEANING

What does primary subtractive colour for light mean?

NOUN · 1 SENSE
1

Any of the three colors that give the primary colors for light after subtraction from white light.