Ruby or garnet (3)
I believe the answer is:
I believe this clue is a double definition.
'ruby' is the first definition.
'garnet' is the second definition.
(I've seen this in another clue)
(Other definitions for red that I've seen before include "- - poker: Kniphofia" , "Bordeaux claret, for instance" , "A colourful communist" , "Colour for danger" , "'If you see it, perhaps you're angry (3)'" .)