For my first 9 level ups I did not get any Loot Box quality higher than the common grade, the boxes with a white glow.
At level 10, I got my first "better than common" grade Loot Box, this time with a blue glow.
Some I have seen from others are boxes that come with purple and orange glows.
I am wondering, are the quality of Loot Boxes predetermined? Am I only set to get the rarer loot boxes when I hit bigger level milestones, such as every 10 or every 20 levels, etc.? Or is the type of Loot Box received completely random and am I just unlucky I guess? In the common box, I actually unboxed a legendary skin, seen below, so glows only guarantee you'll get at least a rarity of whatever the glow is. Contents below: