rgb_line_effect.cs

int pixelPosition = (int)pixelScreenCoordinates.x % 3;
float4 output = float4(0, 0, 0, 1);
if (pixelPosition == 1) 
{
  output.r = color.r;
}
else if (pixelPosition == 2)
{
  output.g = color.g;
}
else
{
  output.b = color.b;
}