#world {
  raster-opacity:1;
  raster-scaling:bilinear;
  raster-colorizer-default-mode: linear;
  raster-colorizer-default-color: transparent;
  raster-colorizer-stops:
    stop(0,#000)
    stop(1000, #00f)
    stop(2000, #0ff)
    stop(3000, #ff0)
    stop(4000, #f00);
}