Obviously it is not possible directly, but an analogy might help.

I sometimes imagine a parallel universe in which people can identify each other by sensing the electrical patterns in their brains, bodies and nervous systems. Each person has a sixth "electrical" sense which means that they can tell if someone is nearby just by detecting their electricity - who they are, what they are doing, etc. - without needing to hear or see them.

In this world, there are some people who "unfortunately" do not have this sixth sense, and have to rely on extra use of their hearing and sight instead.

I think that a blind person might imagine colours in the same way that we would imagine these electrical patterns - by thinking of them as temperatures or textures instead (for example). I imagine the electrical patterns in the imaginary world as flashing coloured lights, because I do not have the electrical sense to detect them as they really are.

There have been some cases of people whose sight have been surgically restored in adulthood after becoming blind at the age of 1 or 2, and who therefore have no memory of sight. Usually such people are bewildered by their new experiences of light, colour, contrast, perspective, etc. One man was only happy with being able to see something if he could associate it clearly with a sound with which he was familiar, and preferred to go around with his eyes shut.