I have always wondered why Five's hair is continually bluegreen.
Someone pointed out that spending months on a ship away from hair salons, the color should have eventually faded and her natural hair color would return.
And then we have the episode where she goes through a Transfer Transit pod.
The pods only duplicate organic matter, so if it was artificial dye, the color wouldn't have been copied as the copy was fabricated.
Which makes me think she had some genetic reprogramming done, to make her hair color bluegreen.
And there is this post from Jodelle on the subject:
Five's hair color