There are several solutions. You can break up the color category into two categories. For example, I have collected a ton of beads in the blue family, so I have organizer cases for light blue, dark blue and turquoise beads. Similarly, I have one for purple beads and another for lavender.
Buy larger organizers than you need at the moment. This leaves empty compartments for each color family so you can add new acquisitions. And buy a few extra organizers in case you eventually need to break a color family into subcategories. It’s very helpful to have cases that are all the same size and shape for your main bead collection, since they can stack/store more efficiently.
I bought the same small parts organizer cases in two sizes - mostly larger cases but also a few smaller ones that I use for jewelry findings, metal spacer beads and specialty categories (such as special artist-made, one-of-a-kind focal beads). You could also use the smaller ones for color categories in which you don’t currently have a lot of beads and then move up to one of the spare larger cases if your collection for that color outgrows the smaller organizer case.