RIT Dye does not contain biocide or corrosion inhibitors. A small amount of dye additive (a few drops) will not cause enough build-up to hamper performance or congest loops, but can variably stain tubing/parts depending on color used, mixture, and loop conditions.
You could alternatively just use RIT Dye to dye the tubing to the color of your choose. Get some RIT dye, a couple plugs for the tubing (if you don't want to dye the tube's inner bore), a disposable pot, fill pot with water, bring water to a low boil/hot, add and mix dye to hot water until a rough desired level is achieved, carefully dip tubing into pot without letting it hit the bottom using tongs (or whatever you find convenient), let cool. Keep in mind, you can repeat this process to get a better coat, use tape to get patterns, mix colors for other effects, and use additives (salt, etc.) to the dye to get more intense/different results. Edited by Falknir - 8/25/12 at 3:32am