If we talk about objects (and they are still part of the universe), then they have all kinds of colors. The same nebulae, for example, look quite mesmerizing due to the "color".
But if we talk about the universe as a space, then it is colorless and that is why it seems to us black (I know, it sounds meaningless, but in fact it is , because it does not emit and practically does not reflect light). Unless it is impossible to call it empty, because there is no vacuum as such anywhere in space.
The universe has no color. In fact, there is nothing there. Only emptiness, which means there is no color. Perhaps the stars. Well, there can be a variety of colors