Can I use semi-permanent hiar dye over blonde highlights?

I want to dye my hair dark purple/violet and have bought a semi permanent hiar dye to try it with but i have been highlighting my hair or the past few years at salons with permanent dye. The stylist hasnt used bleach on my hair when doing this as my hair is naturally dark blonde but i want to know if using semi permanent hair dye could still affect the highlighted sections of my hair permanately, leaving my hair with washed out violet colour. Any advice would be great. The brand of dye i have bought is swarzkopf (sp?) live.Can I use semi-permanent hiar dye over blonde highlights?
semi permanats are scarry!!! the bloned will either turn black bacause its porse from being previously lifted or it will turn a lovely gray ashy color when it starts to fade. why would you dye your hair at home whan you have stlist that hopefully knows what she is doing??? if its money it may cost you more to fix what you do at home, just a thought.