Angry-looking leftist (3)

I believe the answer is:

red

I believe this is a double definition.

'angry-looking' is the first definition.

'leftist' is the second definition.
(red can informally mean communist)

(Other definitions for red that I've seen before include "- - poker: Kniphofia" , "Bordeaux claret, for instance" , "Colour of blood" , "Primary colour" , "See it and become angry" .)

I've seen this clue in the Evening Standard.

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