You don't need anything fancy. Have a fixed port with seal (o-ring in a suitable groove that sticks out just slightly), then suitable drillings in the tool holder that align with the port and direct fluid to where you need it. You'll probably want to add either short flexi nozzles, or fisheye nozzles to direct the fluid to the cutting tip depending on the tool.
The seal doesn't have to be perfect, as a bit leakage shouldn't be of any concern.
If you really want to colour them, then find some oil resistant paint.Anybody know a good way to color the letters so that it doesn't get eaten by coolant?