In Emacs, I want to have line continuation indicators (the curly arrows by default) shown before or after my wrapped text (e.g. in the fringes).

However:

• I don't want want to be able to tell apart my right fringe from my buffer, either by not having a right fringe or by having it be the same background color as my buffer.
• I do want a left fringe, and I do want to be able to tell it apart my buffer, e.g. by having a different background color.

How can I accomplish this?

It would be doable if

• I could set the background of each fringe independently (AFAIU I can't, they share the same face)
• I could show the same arrow line continuation indicator on the right without having a right fringe (AFAIU I can't without a lot of custom buffer manipulation code)

PS: originally I was just going to ask how to set the background color of fringes independently but I realized I could be an instance of the XY problem