I missed this for some reason:

Quoting from the dev's answers (bethesda.net/community/topic/65704/ask-us-anything-dev-answers-6-23/2):

Could we get team-colored shaders for custom games? (with enemy triangles off)
If the demand is high our team would discuss creating a Custom Game
option that could force red & blue team-colored shaders. While I’d
prefer not to introduce options that disable or override vanity
customizations that we’ve encouraged players to collect and personalize,
Custom Game should provide players more control over the way they play
the game.

Start demanding people ;)