No difference in performance at all, as far as I know. Aesthetics is the only reason, color scheme is black so I could have left the black o-rings. I thought it would be fun to try and see if I could see any glow from the o-rings. I can change them back if I don't like it, I've still got the black o-rings.
They are both Bitspower o-rings designed for the exact same size compression fittings, so they should be completely interchangeable.
Bookmarks