The color markings, which you can find above each thumbnail in the image overview and below each opened image, are intended to better capture the different stages of image processing or image selection.
For example, you can mark pictures with the color “green”, which you feel is finished, and your client can set them to “final” if he agrees or downgrades them to “orange” if he still has change requests. This is just one example of many ways you can use the color markers.
We have deliberately kept the functionality open because every photographer and every client has his own way of working. Soon you will also have the possibility to label the three colors in your account settings yourself.