Is it correct without the indefinite article? "A barna erős szín"?
Yes, I just tried and it was accepted.
------- but it does have to have the definite article: "A " barna ero"s szi'n . . .
Big 9 dec 19
Why? I would have missed it in the word selection! :(
What exactly is a "strong" color, exactly?
Intensive, dark, something like that. It can be too much in certain cases. Like if you paint the walls of your home brown, that could be a bit too much.
So, it is a "strong" color, use it sparingly, carefully, in moderation.