<svg>
  <gradientRect x="0" y="0" width="100%" height="100%"
    gradient-type="bilinear"
    gradient-x1="30" gradient-y1="30"
    gradient-x2="100%-60" gradient-y2="100%-60"
    gradient-color1="cyan"
    gradient-color2="white"
    gradient-color3="magenta"
    gradient-color4="green" />
</svg>