Spectrum creators (6)
I believe the answer is:
prisms
'spectrum creators' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for prisms that I've seen before include "Figures" , "Transparent blocks that separates beams of light into all visible colours" , "Transparent glass blocks that separate beams of light into colours" , "Glasses splitting white light" , "Toys that break light up into rainbow colours" .)