*I’m in no way recommending this place yet since I’ve only just placed an order and haven’t seen any examples of their wares.
I found this Falken* place last night when I was looking for transparent yellow 1/8" acrylic. Their selection seems good, especially in the fact that, for each color, they offer variable levels of transparency. The pricing seems decent enough at ~$9 for a 12" x 12" sheet. So I ordered a few sheets and we’ll see what happens!