Dota 2 shader mods
A shader changes how the game is lit and coloured rather than what is in it. It is the cheapest way to make the map easier on the eyes.
The D2PFX catalog has 32 mods in this category. Each changes what you see on your own screen; everyone else sees their own game.
Simple Minify Shader
Wave Lite Purple
Cartoon Shader
Purple Outline
Diretide (outline)
Aghanim Green Lite
Aghanim Purple Lite
Aghanim Red Lite
Aghanim White Lite
Aghanim Yellow Lite
Aghanim Green
Aghanim Peach
Aghanim Purple
Aghanim Red
Aghanim White
Ancient
Haze
Purple Ancient
Wave Green
Wave Lite Aqua
Wave Lite Blue
Wave Lite Green
Wave Lite Peach
Wave Lite Pink
Wave Lite Red
Wave Lite White
Wave Lite Yellow
Wave Peach
Wave Purple
Wave Red
Wave White
Aghanim Labyrinth
Installing any of these
Open Dota 2 Mod Manager, find the hero, press Install. The app puts the file in a free pak slot in the folder your game mounts, tells you when two mods carry the same file, and puts everything back after a Dota patch. The full guide, or the manual route if you would rather do it yourself.