I've found this-clairol semi permanent. Really like it, it leaves a hint of caramel to the hair and covers the greys. It's not semi permanent on my hair though, I definitely had it still in my hair after 28 washes.
I'd tried colouring my hair before, with a colour as close to my own, so more of a light brown but I just found it left my hair looking reddish which I didn't like.