There are so many things to consider:
- Is it girl or boy/man or woman
- Is it short, long or medium length
- Is it spiked, curly, wavy, or straight
- Do you have a fringe or not
- Is it layered or all the same length
...I think my favourite hair color isn't actually a straight hair colour. I like a combination of reds, browns, and just a bit of tanish blonde.
Then for boys I my favourite would have to be bright lime green...because it's cool!