Stata graphs allow you to specify the colo(u)rs used for various graph items. Stata has about 50 named colours, so it's hard to remember exactly what each colour looks like. In addition, Stata uses the names gs0 to gs16 for sixteen shades of grey, starting with gs0 (black) and ending with gs16 (white). These are useful for producing more-or-less evenly-spaced gradations of grey.
To see a plot of all the available Stata colour, you need to install the vgsg package. This package contains useful resources that accompany Mitchell's excellent book A visual guide to Stata graphics. Amongst these resources there a simple command that makes a colour chart.
You install the package like this:
. net from http://stata-press.com/data/vgsg
Click the link to install the package. Once you have installed it, you can issue the command
to print a palette of the available colours. I printed one in colour and pasted it inside my copy of Mitchell's book. Here is the graph:
Notice that Stata has 16 shades of grey (biostats people can't cope with fifty). These are named gs0 to gs16. Of course, gs0 looks black, but if you look carefully, Dougal, you'll see it's actually a very, very, very, very dark grey*. And gs16 simply white.
And there is a second user-written command, by Seth T. Lirette, that I rather like for its elegant output:
. ssc install hue
*For non-Irish people, this is a Father Ted joke. Don't worry about it.