Thanks everyone (and Joe and Sean via PM). These are some good sources, I appreciate it. I really came up dry on my own searches.

BTW I need the tubing for hydraulic lines on my MIG, so I do not want to have to order too much as I do not think I would be able to give the excess away! Not much use for colored 4mm tubing as far as I can tell.

I need about 10-15 feet of as many different colors as I can get (I have between 13 and 19 hydraulic cylinders plus hydraulic brakes, depending on how I decide to do things).

Thanks again,