The Different Colors of Light

When we call something blue, what we really mean is that thing reflects blue light. Energy levels of the atom determine what colors it glows in and what colors it absorbs. There's a second process which is also due to quantum mechanics which is just that hot things tend to glow and they tend to glow at different frequencies. So when your husband looks to you, he can't see that you are glowing in the infrared. You are literally emitting photons right now. They're just not photons in our visible range.