<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<circle r="30" cx="100" cy="100" fill="rgb(255, 0, 0)" stroke="rgb(0, 255, 0)" />
<rect x="200" y="200" width="50" height="50" fill="rgb(100%, 100%, 0%)" stroke="rgb(0%, 100%, 100%)" />
</svg>
in functional notation, RGBA values are also supported.
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<circle r="30" cx="100" cy="100" fill="rgba(255, 0, 0, 0.5)" stroke="rgba(0, 255, 0,5 0.5)" />
<rect x="200" y="200" width="50" height="50" fill="rgba(100%, 100%, 0%, 0.5)" stroke="rgba(0, 100%, 100%, 0.5)" />
</svg>