Copy the whole svn function from the svn-color.sh file to your bash resource file (mine is ~/.bash_profile).
Dont forget to refresh your bash_profile by sourcing it: source ~/.bash_profile
You're done. The svn function overrides the svn executable, which it call directly from its full path.
You can disable colors at any time with the --nocol option.
Copyright (c) 2010 Jean-Michel Lacroix. See LICENSE for details.