I tried using a Sharpie, but the marker would come right off or run with the CA.
I started using paint and would airbrush both the tubes and the blank. I found that if I twisted the tube in slowly and then hit it with a shot of accellerator, it works great and the paint does not come off. If I try to twist the tube in and out after using the CA, the paint will start to come off.
I use paint made for lexan for spraying R/C car bodies as I figure it would adhere well to the resin in the same manner it adheres to the lexan. I use blue, silver, black, and white and have found you can pretty much dictate the final look of the blank by using one of those colors. For example, on light resins I use white and on metallics I use silver and they seem to shimmer even more.