The Mini 2 was a darker shade of Space Gray than the iPhone 6 and 6S. But maybe a bit lighter than the Apple Watch and MacBook version. Sooo..the Mini 4 - which "gray" is it? Closest match?
It's a little darker than the iPad 2, 3/4 lighter than the iPhone 4 antenna bands, a half a shade darker than the space gray Apple Watch with Watch OS1 installed, but definitely NOT Watch OS2, and its .0009 shades congruent to the iPhone 6s screen a trillisecond before the home screen is locked.