3D printing lots of colours

Following my success making a version of the MIDI CheeseBox on a surface mount PCB I now have to make a case with coloured buttons. I’m going to need red, blue, green and yellow. Some of which I don’t have. The good news is that there are folks who will sell you a pack of short lengths (10 metres) of a range of colours at a reasonable price. I think these are intended for use in 3D printing pens, but they should work OK in Edna the Ender 3.