I also got the 13 Mini in Starlight (came from a Silver X). It took me a minute to get used to the matte, color-shifting aluminum sides as I was used to the icy look of the X. I'd counter that the back is almost-white, perhaps similar in tone to the 12 series.
I'll try to post some pics of my phone after work today.
It's a nice, understated color choice. I swap between a cheap black silicone case and no case at all. IMO Starlight and Midnight are the only colors from the base 13 line that allow for flexible case color choice. I'm considering pairing it with that lovely Sequoia leather case this fall.