content: I think a computer would best assist keeping the colors consistent in the frame and matching all grey tones to colors once a couple indexing colors from the frame are established. The sky will be some shade of blue, for example,  so it could start there and present several versions where all objects are consistent with each other. A person would have to make the final choice overall but wouldn't have to question each individual color and possibly wind up creating another of the awful coloring jobs we've seen.