9to5Mac:

While subtle variations in material, texture, lighting, and even the shape of a product can play tricks on the eyes, every device Apple currently offers or has produced in space gray can be grouped into one of several loosely defined categories. Below, we’ve cataloged and categorized the vast universe of Apple’s recent dark material finishes in an attempt to unravel the mysteries of space gray.

At first blush, this seemed really silly. But on further examination, it’s fascinating how many variations Apple has had for “Space Gray”. You’d think a company renowned for its attention to detail would be more consistent in its colour schemes.