After a Ryujinx update, delete your old shader cache. Old caches often cause graphical glitches (rainbow colors or invisible characters).
If you have ever tried to play Tears of the Kingdom or Pokémon Scarlet/Violet on Ryujinx, you know the pain: The game freezes for a split second every time you swing a new sword or enter a new area. ryujinx precompile shaders
Stop the Stutter: A Complete Guide to Precompiling Shaders in Ryujinx After a Ryujinx update, delete your old shader cache