ImageSorter is a free tool which organises and sorts images by colour.

We pointed the program at a folder, and it quickly read 270 images, presented them in thumbnails, and sorted them into colour and layout.

This worked surprisingly well. Cityscapes, faces, forest scenes, sunsets and more were generally grouped together, making it easy to spot duplicates and find similar images.

Double-clicking any image opens it in your standard viewer, and there are tools to copy, move or delete selected images.