Well if I were to have to choice to take someone or not I'd probably rather have somehow with their natural color then blue, green and flashy red. Doesn't really make you look mature. Not flashy red, so how YJ has it would be fine.
The problem with people is that they make the assumption about "odd" coloured hair. I've had my hair dyed pretty much every single colour you could think of and I was way more mature than anyone my age (I had those colours done as a teen). I just love being different so that is why I always do something others can't or wont do just so I can stand out. People immediately dismiss anyone with a funky haircolour because they think they're a punk or immature but they don't ever think that a person could be doing it to be unique, which is why I did it.
The only reason I don't have punky coloured hair now is because I have toned down. I still have some purple in my hair but my main haircolour for the past years has been red. I have only recently changed it to black and dark purple because it seems that people at work started to copy me and go for the same haircolor (red) so I figured that black and purple would be a little too "bold" for them to attempt so I can be different again.
Anyways, before I ramble on more useless shit, the point of my post is, people shouldn't be judged by a haircolour. Having a crazy colour says a lot about a person, including the fact that they are bold and outgoing.
That is exactly why I dye my hair bold colours, I hate being like everyone else.