Hve you had highlights before? Try a few low lights in between to gently introduce colour to your hair and keep adding it till you find a shade that you are happy with. If you have been dark most of the time I would rather you try a subtle change than go for the full monty all at once. You might like the new change or even love it but eventually it won’t feel the same and then you would have damaged your hair all at once for nothing. I always suggest clients start off small – that way they can get a feel for what they might want without the full commitment of damage and loads of repair later.