<arena ...>
...
<box id="box1" size="0.75,0.1,0.5" movable="true" mass="2.5">
<body position="0.4,2.3,0" orientation="45,0,0" />
<leds medium="id_of_led_medium">
<led offset=" 0.15, 0.15,0.15" anchor="origin" color="white" />
<led offset="-0.15, 0.15,0" anchor="origin" color="red" />
<led offset=" 0.15, 0.15,0" anchor="origin" color="blue" />
<led offset=" 0.15,-0.15,0" anchor="origin" color="green" />
</leds>
</box>
...
</arena>
While giving color to movable obstacles. what syntax must be used to give custom values for r,g &b.