Donald Bailey’s Pith Helmet 2 are “are an innovative set of rules that are condensed onto a single Quick Reference Card to play with. Mr Bailey has kindly made his system available for download on this site. The link has an archive or resources and the QRF and rules and much more.” From www.britishempire.co.uk
The Portable Wargame project has a set of Colonial Rules. These rules are designed to be played on a square, checkerboard like grid.