matplotlib: Help! I need to plot colored regions based on a set of boundaries

[John Crockett]

I am attempting to plot the relative sky positions of several Astronomy images I'm studying.  I want a set of axes that represent a 2-d projection of the sky (don't want to use polar projection), so my x-axis would be from 0 to 360 (right ascension) and the y-axis from about -35 to 90 (declination).  I have the RA and Dec of the edges of each of my images and I want to plot the "image" as a colored rectangle, to-scale on my axes.

How do I give matplotlib instructions to color-in a region of my plot based on the edges of that region?

Thank you for any help you can provide.