Identifying Images with Indexed Color Format

[roscko]

I am simply trying to filter out images that have an indexed color format. I was hoping there was some property I could pull from running an identify but haven't had any luck. I have tried checking the unique colors to see if we fall under 256 but this returns false positives. Does anyone know of a way to determine this through an identify (verbose or otherwise)?

[fmw42]

convert logo: -type palette -format "%r" info:
PseudoClassRGB


Or get the Type from the verbose info: which will say palette or palettematte. That will mean pseudocolor.