i'm glad you could get your printer to work. enabling color is quite easy as well. u got the first step right. you need to open up your browser and go to
localhost:631 (without any www. or nothing). on the page that comes up (a screenshot is below) go to the "printers" tab on top then click...
here is the drivers put together for HP color laserjet 1600
no terminal etc. needed. installation is pretty straightforward. i also included other cheap printer drivers such as minolta 12xxW-13xxW (ie 1350W).
here is the link for the download.