Hi, I have blonde hair but wanted to go lighter so I put a dye on it but it went yellow/orange what can I do?

For the most part I find blondes are just not happy being blond. You should have used a spray in lightener which are found in most good pharmacies. Dye should not have been used. Now you will have to tone it down with another dye to balance out the colour.

I suggest you seek professional help to get rid of the yellow/orange.

Tick

I have to disagree with tickle. I find that spray-in lighteners (simply hydrogen peroxide) are great for making your hair brassy orange.

You'll either have to dye it darker or you'll want to bleach and tone (double-process). The fundamental problem is that hair becomes yellow/orange as it processes. Eventually, it will get to yellow/pale yellow, but that requires either very light hair to start with or bleach.