Once your color is mixed, it starts working right away and can’t be saved, stored, or split to use later. Mixed color loses its strength quickly, so saving it for later can give you uneven or unexpected results. Pressure can also build up inside a closed bottle. Mix only when you’re ready to apply, and use everything in one session.
When you’re done with your application, throw away any leftover mixed color, along with the bottle and gloves, right away in a covered trash can. That keeps it out of reach of children and pets. Don’t pour leftover color down the sink or toilet.