I've got dark blonde hair which is highlighted every 6-8 weeks. But I am getting lots of grey hairs poking through in the roots after about 2 wks. I work in a youth-orientated office unfortunately and I dont want any grey hairs showing. I cant keep pulling them out or I'll be bald lol. I've asked my hairdresser if there is a hair dye (dark blonde ideally) that I can apply to my roots that would blend with the highlights to hide the greys but she says no. She wants me to come into the salon to spend even more! 
She did try an overall brownish tint to my roots instead of half a head (still cost me £40!!) and the greys were visible after about a week so the dye was rubbish. AIBU to expect to be able to cover up the greys while my hair grows between highlights? I also wish I could dye my own hair dark blonde (to cover the greys) and apply my own highlights over it but I think thats a bit ambitious lol! Would save me a fortune though 
Anyone got any tips or suggestions to cover up the pesky greys?