itch.io

1. Copy the transform MVNVignette block from the MVNRomFXTemplates.rpy file and put it anywhere (a new file called MyRomFX.rpy makes it easy to find). 
2. Change the name to
   transform MVNVignetteGreen
   or whatever.
3. Change the u_vin_tint to whatever you like. eg:
   u_vint_tint (0.1, 0.8, 0.1)
   for a green.
4. Then you can call it eg:
   camera at MVNVignetteGreen

You can change all the other parameters too. Everything is commented nicely so you can figure out stuff. 

If you check transform OtomeBrains that is a vignette with a different colour so you can see what is changed. 

You can do this for any of the other effects too to make custom ones.