Hi I have just had blonde highlites put in with bleach,I jhate the colour it has come out as.Can I get a supermarket dye and dye it straight away.

You can use dye off the shelf, but remember that the highlights are going to be porous and will absorb the dye differently than the rest of your hair.

My suggestion is to go to a beauty supply place and get a toner to put on them to make them more subtle.