How do you automatically colorize program outputs in a bash shell?

I want to take any program that outputs to the screen, catch the output, and colorize certain keywords before they are output to the screen. For example, here’s the normal program output:

bash# <program>
blah blah blah       <-- this output has no color

vs.

bash# <program>
blah blah blah       <-- this output is colorful

Ideally it doesn’t matter what the program is. I’m just looking for a good way to incorporate more color into my konsoles.

Edit: Sorry, should’ve been clear. I’m not trying to just colorize shell script outputs.

How do you automatically colorize program outputs in a bash shell?