I was using linux ubuntu for my work now I’m using Mac OS X 10.7.3, I was surprised when I did ls command, the ls result returned had the same color for files and folders. Fortunately there is a trick to set ls command with colors.
Create or edit this file
~/.bash_profile
Then insert this inside it
export CLICOLOR=1
export LSCOLORS=ExFxCxDxBxegedabagacad
Save it, now open your new terminal instance.