Hello Guest 'Fire in Blue' would not mean 'blue fire', unfortunately. 'Lady in red' is fine, because 'in' can be used to imply 'wearing': the lady is 'inside' the red. But fire is not inside 'blue', when it's 'blue fire': it simply is blue.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.