Feature Request: Colored number diffs

[KarateSnowMachine]

Thanks for such a neat little tool.

I have been using it for watching the output of df -s and one really useful feature in the diff mode would be to detect if the character is a number. If so, change the color to red or green depending on if that digit decreased or increased. I haven't looked at the code but I suspect this might be a somewhat simple change to make.