For the record, this was printed with Anycubic Clear resin, though I suspect similar clear resins would work just as well.
Treadwell's lenses are not colored, but you never know what people may try to build. I've seen ordinary food coloring being used to tint the clear resin before printing BB-8's holoprojector lens. I know food coloring is water-based, but it seems to work, so that's something to experiment with if you don't want to buy transparent colored resin just for this sort of thing, or you want colors not available (like highlighter dye).
Treadwell's lenses are not colored, but you never know what people may try to build. I've seen ordinary food coloring being used to tint the clear resin before printing BB-8's holoprojector lens. I know food coloring is water-based, but it seems to work, so that's something to experiment with if you don't want to buy transparent colored resin just for this sort of thing, or you want colors not available (like highlighter dye).