Generally, as a rule, I always hyphenate words to make them into a single adjective, so I've been putting "blood-red", "forest-green", "royal-blue" and the like, but the moment I typed "royal-blue", my instincts kicked in.
It didn't look right to me. Perhaps it's because this is an official colour or the fact that the word "royal" is unrelated to blue, but I'm not sure.
What do you guys think?
P.S. I'm using British English, if that helps.
Best Answer
You would not use hyphens when the phrase is used as a noun:
Generally, I'd recommend that you use hyphens when the phrase is used as an adjective (i.e. a compound modifier):
However, if the color phrase is part of a larger adjectival phrase where the color phrase itself is being modified, leave the hyphens off:
There may be still be some disagreement on this, though, and there are no absolute rules that apply to all possible word combinations. You are free to use whatever form you feel is most natural and easy to understand.