Limit screen colour palette with URP

I’d like a way to define the list of colours that my scene renders too - so every pixel would be approximated to the closest colour in the defined palette.

I’ve achieved this in SRP using this GitHub - oxysoft/RetroSuite3D: Some image effects and shaders to achieve a retro look in Unity - but this doesn’t work with URP.

The best I’ve managed in URP is using a LUT, but LUT’s will show you in between values that don’t exist in your LUT so it’s not the perfect solution. Someone ran in to the same problem a while back but didn’t get any response

Has anyone managed to solve this problem?

I cracked this by going with the route described here - essentially adding a custom material/shader to a rendered raw image