I have this alien race of amoeba-like creatures about the size of humans with the ability to morph their shape and move by constantly making and dissolving muscles by manipulating their membrane and bursting capillaries.
But these muscles cannot be permanent and making smaller ones is much harder for them than making bigger less specific ones. And this is a problem because their language is mostly based on color and how color changes on the body of an individual.
And other animals do this through muscularly manipulating chromatophores but since these muscles would to hard to generate in these creatures what would be a viable mechanism for rapid color changing like in cuttlefish?
(I had an idea on doing it through oxidizing and de-oxidizing vanadium but I'm not to sure on how fast it can be done and if their are enough colors from it to form a complex language)