Very cool first attempts! an excellent and cheap flashlight to use with tubes is the Convoy S2+ but if you can afford it I highly recomend this one. You can also put a cheap RGB strip with controller in a diffused tube and cover parts of it with transparent or reflective materials. There are some tutorials online that explain how to make light painting tools but best is to start experimenting with any light source or shiny or transparent material you can get your hands on. There are blades, tubes, optical fibres, etc.. The tool doesn't have to look great. It's what it can make that matters.