The red light accentuates the strand of fiber optic wrapped around the human hair. The light catches in the piece of fiber in a unique way.

The white light striking the prism from behind splits into many different light colors.

There is a blue wash on this picture, creating the effect of a movie screen. The light may be caused by a screen, but probably not.

In this picture, the color of the light is caused by passing through colored glass. Unlike the prism, the light is not split into different colors, certain colors are blocked by the glass letting the colors we see through.

The colored ice cubes seem to be illuminated from within. Looking at the picture, I can't determine where the light is coming from, so from the cubes may be the best option. The glass itself is lit around the rim which may be from the light behind and below the cubes, but i can't tell from the picture.