For colored ls output I would recommend installing the gnu coreutils and using that version of ls instead. For either version of ls you'll need to pass the correct flag to it, which is --color for the gnu version or -G for the standard OS X version. So you can do something like
alias ls='ls --color'
in your .bashrc.
To color your prompt you'll need to use the correct colors codes for your terminal, but mine uses
PROMPT="$(print '%{\e[0;38m%}%{\e[1;1m%]%}[%m:%c] %n%%%{\e[0m%}') "
to produce
[hostname:directory] username%
in bold white.
