This is very awkward sentence that no one would ever say where i am from.
"It's super colorful; I hope it's not too much..."
"No, no. Colorful is good!"
Would "Coloring is good" be an acceptable translation to a native speaker?
Not sure about coloring, since ive never seen such word related to colorido, but sometimes i see colored.
I put in "coloured is nicest" and I think it should work as well.
What about "colorful is nice"?
Given that the first definition provided by Duolingo was " colored, colorful, coloring," it seems a bit unfair to not allow "Coloring is good."
You're thinking of coloring as in the act of coloring. "The coloring is good" (with "the") might work, but it's not talking about coloring as in using crayons (etc.); it's talking about the coloring (the colors) of something.
Since 'colorido' is an adjective, would 'colorida e boa' be correct if a feminine noun was being referred to?
Yes. It is also right.