Let's stop calling bits per channel "color depth"

Crusades can be tiring. They can end up in defeat. They can also end up being not much more than tilting at windmills.

There's all sorts of historically inaccurate things about color and just about any other subject that can try a person's resolve in seeing the larger body who use certain terms change from their historical inaccuracies. About the best you will be able to do is use your preferred language and be ready to explain what you mean if it is not readily recognized by the readership.

Color depth is also commonly called bit depth, which I think is more accurate. I view your preferred term(s) of "gradations of color = color resolution" as explaining the ramifications of greater/lesser bit depths.

Good luck...