User blog comment:Pancake2/I just learned something the hard way - Read this so you won't have to!/@comment-2128395-20100902084746/@comment-1874176-20100902090045

That has to do with the color reception of the eye (and brain), I think.

If you have light in one color for a longer time, your eyes and brain get used to it and filter the color out. If you have normal light again then, your brain needs time to re-adjust, meaning in your case, it kept filtering out the green parts of the light (physics: normal white light is a combination of all colors), so the colors were messed up for some time.