When is it appropriate to use a hyphen when naming colors?
For instance
Blue-green
has a dash butTeal blue
does not.Is there some general English rule that applies?
Answer
Generally one uses a hyphen for compound adjectives where they precede the noun or noun clause which they describe.
For example, I would write ‘A blue-green sea provided the background curtain to the open-air theatre’.
But I might equally say ‘My favourite colour is blue green’, and ‘I love being in the open air’.
Attribution
Source : Link , Question Author : Lourens , Answer Author : WS2