Painting utility room with gypsum plaster - Which color?

Yes, I contradict my own arguments because I now think: maybe it's a bit exaggerated?! But if I were to look for a suitable, diffusion-open paint for the gypsum plaster, what could I use for that? And then not prime at all ("Plastiksuppe")?

Nobody have an opinion on this?

Primer and dispersion paint...Ende