Once you buy the tub (either the smaller or larger one) you can place any GULP in it and the colors will NOT bleed into one another.
I bought a large tupperware containers and placed the juice of 3 large GULP buckets in it then placed a bunch of assorted GULPs (squid, shrimp and swimming minnows of various sizes/colors) in it. Before I go fishing a take a smaller tupperware container and grab a handful of GULP and pour some juice in & I'm good to go. I keep the small container of GULP in my cooler while fishing.