A bright red temporary colour was applied to 70% white hair-How to resolve the problem?

well you could add low lights a darker color to balance your red color or you could add high lights to brighten up the red color it all depends on how you want your look to go or you could color your hair a different darker color to get rid of the red color all in itself...it all depends..

A bright red temporary colour was applied to 70% white hair-How to resolve the problem?

You can use a color remover to remove all of the pigment. Then re-dye it to the color you want.

A bright red temporary colour was applied to 70% white hair-How to resolve the problem?

Red is hard to remove especially on white hair which has no pigment I have to agree with Christie do low lights because once the color fades most likely it will probaly turn orange.Or you could add brown to it all over to tone it down.