Consider the concept of green and the color green. Is it right to say that the concept of green is also green? I would think not, since the concept merely reports what the color green is like. It itself is not green. Concepts seem to be analogous to, say, a cardboard box that you put a piece of bread into with a list of facts about the bread on the front. You would never say that the box is like the bread; it only contains bread and describes the bread. This question could probably be expanded to any concept, including justice and the like.
It's been said that "colorless green ideas sleep furiously" but this is nonsensical - possibly poetic.
Are Concepts Colorless?
Yes, concepts have no color. It would be a category mistake to describe them as so, else it is poetry. Unlike color, which is prismatic range, concepts do not exist - they are only to be found in language.