Sorting a large amount of images based on saturation / brightness

I am a multi disciplinary designer I have a large amount of photos of the blue sky. I wish to group them into a number of groups ( maybe 5-10). I plan to distinguish groups based on saturation and also brightness. It would be good if I could use a certain algorithm / program for different sets of images. I would love to discuss this with somebody and pay for a program to be written.