My snap install by default was set to 64k colors, but 16m is an option.
The ArcaOS installer always installs SNAP and Panorama at 64K colors. The user needs to change it, every time. Once it is set properly, the setting usually survives driver and OS updates.
I have no idea why they do that, it would seem that somebody, at one time or another, had a problem, so they play safe, and everybody suffers. FWIW, I do have one old DELL system (4300 series) that needs to run at 64K colors, but I think the main problem is that I am using an old TV at 1360x768 resolution, as a monitor. The video adapter only works at 1024x768, 800x600, and 640x480 though (even in win XP, which doesn't work very well). The old TV does run okay at 1360x768x32 on a newer system, so it is obviously the adapter that is causing the problem. That old system is really garbage, and I probably should get rid of it, but it is good for testing new releases of ArcaOS.