Rubygame is a cross-platform game and multimedia library for the ruby programming language. It provides flexible high-level ruby classes on top of SDL to make game programming enjoyable.
Rubygame 2.2.0 adds a new module with color-related classes and pre-defined palettes of common colors. It also adds the ability to set the window icon, change the value of individual pixels on a Surface, and several other improvements.
Project Summary: http://sourceforge.net/projects/rubygame/