It is impossible to describe any colors to a born-blind man. Since, seeing is a very special sense of five senses which allows one to have a direct experience or perception of the colors of things. Being born as a blind man means being cut off with the colors of the natural world. Even though, some one might try to describe a color to a blind man by associating with some thing else such as, red is associated with hot...This way is nothing esle but a way of using a feeling of hot that might lead to a conceptual or imagining experience of the color, not a real experience by acquaintance. Hot is hot. It can not be used to substitute for red. Red is not hot. One sees color, not see hot.
Focusing a torchlight on his eye-lid on and off
I'm not sure why you'd need to, but I'd say that white is the color that stays most cool in the sunlight, and black gets the warmest.