I have used linux for a few years but color coding directories and executables (and soft links, and ...) in shell text are a mystery to me... They are either on automagically and I enjoy them or they aren't and I don't bother to try to turn them on...

I use tcsh shell and various flavors of Linux including the main ones RH, Slackware, and Suse. but I have noticed that some have good colors (for shell text) and some don't, also some have default shell of bash with nice colors but when I switch to tcsh I lose all that... But slackware seems to have the best color coding for tcsh I have seen (lighter colors so it works well in dark or light background) but getting to my point...

How do I control the colors?