I currently dye my hair with a home dye kit - a mid brown colour. However, the colour builds up over time, and it's now too dark. Can you buy root-only dye kits? I've looked in a big Tesco, but couldn't see anything - could you use a normal hair dye kit and just put it on the roots? [bit wasteful - but still cheaper than the salon!] Also, is it hard to really match your natural shade?
Sorry for all the questions, thanks in advance! 