Does anyone have ay resources on which hair colours suit different complexions?

I generally go dark brown or black for my wigs but I'm feeling like a change, not really got time to try on a whole load of different ones and haven't got round to trying out any of the apps or software around.

Thanks x

The iPhone app - hair colour - does help if you get a decent photo of yourself to use. But in the end it's down to trying some on. All I know for sure is that I went to one shop and after 20 minutes and 8 wigs I put one on looked at myself and went - yep that's me.