Excellent tutorial @Anubis I was planning on making one but this is far better than what I would have made!
I have actually dyed @MBS fivestar hubs with pretty much the same steps as above but without the vinegar.
I dyed them for 3h at boiling temperature on gas stove under full supervision
Lol
I boiled for so long because the hubs take AGES to absorb… and not, may I say, very well.
Also the hubs were completely degreased and clean before hand, so was the pot.
Here are the results
=
The one on the right I scratched with 400 grit before to see the difference… as you can see it’s worse and it’s hardly a royal purple… More like a washed out indigo colour.
Then attempt No. 2 (the other half of each hub) was like a double fail… I used the same method as before but with this colour
And 2h later the hub hadn’t dyed AT ALL.
So I had some midnight blue and added that into the mix a 3h later I got this…
It’s a nice colour but definitely not midnight blue, more like a light navy blue
I’ll let you be the judge. The next colour I want to try is yellow but I don’t have any hubs left to try it on… @MBS? 
NOTE
The hubs don’t seem to deform at all the first test i had the hubs screwed together the second time i had each half loose, the result is 100% the same.
i also took a stanley and cut a chunk out in an inconspicuous spot, the dies get’s absorbed about 2mm, no more