Want to go blonde

Hello everyone!  I have almost tailbone length, naturally dark brown hair that is colored medium neutral brown w/ golden blonde highlights.  I really want to go blonde, but according to my colorist, my hair would be completely wrecked.  I've gone through a few color changes in a relatively short time span, so, even though my hair isn't fried, she said that it will be if I'm not careful.

I came up with an idea that I wanted to run by the board before broaching the subject with my colorist....  What if I ask her to heavily highlight my hair?  The highlights I have now are chunky, but aren't very heavy, so, perhaps a very heavy highlight would give the illusion of being blonde?  Friends of mine seem to think that the blonde will become brassy very quickly and I will hate it.  It's not brassy now, so, why would adding more highlights make it brassy?

Thanks! 

If I was you then I would deff NOT bleach your whole head, doing so WILL FRY YOU LONG HAIR! It will take you years to grow out any damage! Have your colorist try this, apply a super ashy dark blonde or light brown hair color. Do a deep conditioning treatment on your hair then a light trim. After do a very heavy full head of foil highlights. After that try to let her cut off 4-5 inches of your ends and lightly layer your hair. Then once a week you should apply an apogee treatment for damaged hair http://www.aphogee.com/aphogeetreatment.cfm  (get it at sallybeuaty) this will keep your hair iN great shape.

BUT PLEASE IF YOU READ NOTHING ELSE I HAVE WROTE, PLEASE PLEASE PLEASE DO NOT BLEACH YOUR WHOLE HEAD. IF YOU DO YOU WILL HAVE TO CUT YOUR HAIR OFF, AND IT WILL TAKE YOU 4-5 YEARS TO GET IT BACK! ALSO DO NOT TRY THIS AT HOME!

Thanks for your suggestions, Fabulous and Moffpoff!

Fabulous, could I ask my colorist to do the process you mentioned, without cutting off 4 or 5 inches off my length?  I really don't want to cut my hair, other than maybe a little trim.

Thanks again!