Breechplug
The color coding on the tef tapes indicates its thickness, and not all tape is of the same quality. As UC suggested Oatley is one of the better brands.
One thing you need to detirmine is what thickness of tape do you need to mate your breech plug to your barrel. I have all three tapes but have yet to find a BP that I would use the yellow on - it is really thick. When you tape the plug - tape from the muzzle end back to the breech (make sure that you overwrap the nose of the BP) andmake sure that you are turning the tape in the correct direction. Then when the tape is on the plug - 'seat' the tape on the nose andturn the BP in your fingers and gently press the tape down into the threads. Now, when you start threading the BP into the barrel it should turn in very smoothly with only a SLIGHT' bit more torgue than if it had no tape. Your goal is to get the tape to go in with out tearing -pulling - or balling up - a smooth application. The thickness of the tape will detirmine how this whole process works.
I use one wrap ofpink in two different rifles and one wrap of white in 3 other inlines... find the right tape for the right gun.