I am pretty confused about it all, too.
I found this video and I find it helps me understand what orange gear is all about. From what I can tell, when stripped of all mods, all orange gear has the same rating. All stats are dependent on the mods installed. So, this allows you to customize your appearance by keeping your favourite looking gear and upgrading with newer higher level mods.
Hopefully someone will join to correct me if I am wrong.