I've been colouring my wife's hair for a few months with a kit that has two liquids mixed together.

Would it be possible to store the leftover combination of liquids, rather than discarding it?

Thanks for the information, Mol. I hadn't thought about the possibility of freezing it. I usually have about half of the mixture left over.

I am a little concerned about trying to save it though, in case the results of the stored mixture were unpredictable on my wife's hair.