What does the existence of a color photograph of my grandmother as an old woman have to do with my desire to colorize a grayscale photo of her as a child? Or colorize the photos of her wedding?
It's a very strange argument to make: there exist some photos therefore other photos may not be colorized!
Did you colorize grayscale photos of your grandmothers wedding?
Seeing that a "neat tool" exists and using that "neat tool" are two diffrent things. Google Glass was neat, too.