It might be because I am using a cheap adapter for my retrotink but even by itself utilizing Dreamcast S-Video the colors are clearly misinterpreted, the Dreamcast signature swirl is blue instead of red, would sending this to StoneAgeGamer for a firmware upgrade fix both of these issues or would I just be better off to get a Koryuu to integrate CVBS and Y/C signals into my setup?
I would recommend using an HDMI to Component converter when pairing the RetroTINK with the OSSC. I have tried several HDMI to VGA converters, and the results were always unstable (with a lot of noise/movement on pixel edge boundaries). Because AV3 has limited LPF options, using AV2 for signals being passed through the OSSC is a better fit.
For AV3, I use a breakout cable to connect my 6th gen consoles via component – their output is a lot less prone to noise.