ShaderLab implementation of color-dithering and pixellation screen-effect.
The palettes determine the colors used by the shader. They are implemented as Scriptable Objects and can be created from the menu-item "ScriptableObjects/Palette". I recommend searching for great retro palettes at https://lospec.com/palette-list
NoiseFactor determines the strength of the dithering noise. Increase for a more "pixellated" look