take it from someone who dyed their hair a different colour every week – don`t use the supermarket dyes!
The best way to get the results you desire is to go into a Petra Hair Care/ Hairhouse Warehouse or Price Attack and get the colour in a tube and the activator in a bottle.
The reason getting the solutions in this manner is better is because the store bought kit`s almost always have a higher peroxide volume than what is actually required!
Without seeing your hair, I would say you will probably need to mix the colour with what`s referred to as 20 Vol peroxide. The 20 Vol will lift the colour of your hair and allow the new colour to be deposited without damaging your hair to the endth degree.
The way to use these mixtures is a ratio of 1:1 meaning if you use a 60gm tube of colour you will use 60ml of peroxide solution.
If you go into hair house warehouse or one of the other stores mentioned they will have colour charts and be able to help you choose a colour that is suitable for you 🙂