Unfortunately, I would have to say no. This is beyond the scope of a small, fast, self-hosted PHP gallery, and is not required by many users. The feature you are requesting requires intense work on the server (PHP) to study the image (pixel-by-pixel) and then store the output somewhere ... It's too slow to recreate every time the folder changes.
How would it generate the color palette based on the response from the PHP? How do we know if an image is "yellow" if it contains only one pixel that is "yellowish"? Have you seen any other PHP applications that can do this? This is an expensive feature that would require a lot of development (also for the interface) and should probably be created and hosted as a dedicated solution. It's too complex for a light gallery.