The tubes are easy but the others have to be injected and you will have to create a prototype, some molds, and some injectors. I looked into have a mold made but the mechanist wanted $400 so I opted to make my own. It was a long and tedious process.
To do the tubes all you need is some melted, colored plastisol and any kind of rod. Dip the rod into the plastisol and raise it up. Let it cool a couple of seconds and dip it again. Stop when it is the size and thickness you want. You can fashion a cutter or there are ones that you can buy.