Lightening Darker Ends

Oh dear. So before my whole journey into blonde-ness, I had a very dark, permanent colour in my hair. My hairdresser eventually bleached it out using highlights (after many attempts and months of me with inbetween coloured horrible hair).

Though the dark colour is gone, it's not forgotton. As my virgin hair grows through, and is bleached, it is lighter than the ends. The ends have an orange tinge to them. Lately I've been trying to bleach them out with some success, however, I know it's really bad for the hair dye keep bleaching the ends. I'm going to apply Wella White Lady with 20 vol and concentrate on the ends.

I got a big chop recently, so not looking to do it again.

Is there anything else I can do? It's so annoying!