dolphin/Data/User/Shaders/nightvision.txt

uniform sampler2D samp9;

out vec4 ocol0;
in vec2 uv0;

void main()
{
  float4 c0 = texture(samp9, uv0).rgba;
  float green = c0.g;

  if (c0.g < 0.50)
  {
    green = c0.r + c0.b;
  }

  ocol0 = float4(0.0, green, 0.0, 1.0);
}