Every kid who first looks into a telescope is shocked to see that everything's black and white. The pretty colors, like those in this picture of the [Sleeping Beauty Galaxy (M64)](http://apod.nasa.gov/apod/ap110612.html), are missing:

[![M64](https://i.stack.imgur.com/jCLh5.jpg)](http://apod.nasa.gov/apod/image/1106/m64_hst_897.jpg)

The person running the telescope will explain to them that the color they see in pictures like those isn't real. They're called "false color images", and the colors usually represent light outside the visual portion of the electromagnetic spectrum.

Often you see images where a red color is used for infrared light and purple for ultraviolet. Is this also correct for false color astronomy images? What colors are used for other parts of the spectrum? Is there a standard, or does it vary by the telescope the image was taken from or some other factor?