I found the 'Output' text difficult to read on the original, and messed up a couple prints by not pausing at exactly the right time to make the indicator a different color. So, I changed it to have the outer shell and indicator a second color.I used MakerWare's medium. I recommend 2 shells, 0.27mm layer height, and pretty fast (I did 90 mm/s). This helps with many issues from switching printing heads. Slower speeds can leave one head with PLA sitting in it for long periods, causing flow issues and clogs. Lower flow from smaller layer height does the same thing. I occasionally had problems with a single shell due to a couple messed up gear teeth since there is only one chance to get the outline correct and there were sometimes flow issues switching colors. This is no problem if it goes over it one more time with a second shell.