I currently used a loreal product to highlight my hair. I was trying to go blonde, but the colour turned out brassy or reddy. How can I correct the colour to get rid of the red tone and get a blonde colour

Sweetie, keep in mind that dark hair contains a lot of red pigment in it. And if you apply a lighter hair color on dark hair, it will pull red tones. To go from red to blonde, you will need to pre-lighten your hair to a yellow stage and then apply the selected color.

There is a product called red/gold corrector you can buy in beauty supply stores. I forget who makes it, but you would find it with the hair color. It is purple liquid and would come in a little dropper bottle. Next time you color, mix a few drops of it in with the color.

Your main problem is using cheap drugstore color to lighten. I always use this stuff called Kaleidocolors... it's a blue powder and you mix it with 40 vol. developer (higher volume developer= better lightning power). It is specifically made for lightening black to dark blonde hair. It is what they use in salons, and it is the absolute best, in my opinion. I guess any blue powder would suffice (blue neutralizes the red). I usually buy it (and the red/gold corrector) at Sally Beauty Supply... don't know if they have those where you are, but you can also order online, I suppose...

Ardell makes the Red Gold color corrector found at Sally's. It also comes in a one time use tube good for any hair dye -

Also, Ardell makes UnRed which removes the red.

Loreal Excellence Crème used dark blonde(natural) but my hair was medium brown with gray wanted to lighten my hair and keep red out colored 24 hours ago