You can add colour treatments to your gesture using the Avatar Effect LUT script.
When you import a texture to apply as a LUT you should apply the following settings to your .png file;
Texture Type: Advanced
Mapping: None
Import Type: Default
Bypass sRGB Sampling: ticked
Generate Mip Maps: Off
Wrap Mode: Clamp
Filter Mode: Bilinear
Aniso Level: 0
For more information on creating LUTs, see Unity's documentation here; [1]
You can add audio effects, synchronised with other events in the gesture, using the Audio Effect component;
For more information on audio files and Unity see here; [2]