Anaglyph-fabric

Requires: ClothConfigAPI; ModMenu

Red-cyan by default

Options (in ModMenu):

• Eye separation (Instructions below)
• Eye angle (set to 2⋅tan^(-1) ⋅ (distance between eyes)/(2 ⋅ distance to monitor) for best experience)
• Glasses RGB ( FTT for red-cyan, TTF for blue-yellow, etc)
• Crosshair rendering (as it is very distracting to aim with two of them)
• Grayscale fog (overworld one is blue, nether is red - both very bad for R-C glasses)

Nether has a very bad color scheme, so play a few hours in overworld first. Recommended with something like https://www.curseforge.com/minecraft/texture-packs/pack-and-white to get used to the unusual eye position in Nether. You really should play around 2 days with it

Don't look at diamonds/lava until you feel confident with colors

Source