Transition from "white" to rgb, not from current color

I've some trouble to understand the color transitions:

const ctrl = "wifilight.0.192_168_178_37";
function rand(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}
function setRand() {
    const cmd =  `r: ${rand(0,100)}, g: ${rand(0,100)}, b: ${rand(0,100)}, transition: 3`;
    setState(ctrl + '.command', cmd)
}
setInterval(setRand, 3*1000);

on every trigger the color switches to white and transitions to the rgb value. I would expect to have the transition from the current color.

soef / ioBroker.wifilight

Transition from "white" to rgb, not from current color #20