Run
dircolors -p > ~/.dir_colors
to create a config file with the default settings in your home directory. Then edit this file to change the color scheme to how you want it and run:
eval `dircolors ~/.dir_colors`
You will probably want to put this in your shell startup script (usually .bashrc, assuming it gets sourced from .bash_profile).
Unfortunately, I can't find a site that lists all the different colors so you may need to experiment. I found
this site which has some good information.