almost embarrassed to ask but I just processed my first roll of color with Unicolor kit and can't find out if you're supposed to toss it out as one-shot or return it to the container and draw off what is needed for the next roll(s)?

I read where people are getting 12 or more rolls from a liter but at 8oz per roll that can't be done. So I assume you return it to the original container and reuse it?