LIFX Developer Zone

HSBK clarification

With HSB set, I think there’s theoretically no need to use K. However, other discussions here mention using K to tint the color resulting from the HSB settings, in a sort of post-processing? Is the effect of K value documented somewhere? If I use a zero value for K, will colored devices ignore it and use only the other 3 parameters?

Hi,

The maths is a bit complicated, but essentially the amount of influence the kelvin value has is inversely proportional to the amount of saturation.

So when saturation is at 65535 (the most saturation) the kelvin has no effect on the light, but when saturation is 0, then the “temperature” of the white changes and it goes from more orange to more blue as kelvin increases.

(note that the http-api uses scaled values for hsbk, so saturation of 1 in the http-api is 65535 when sending packets to the device)

Essentially, if you have full saturation, kelvin makes no difference.

Quick follow-up: is there a way to eliminate the effect of kelvin entirely? For example, using the color temperature of the sun, which is 5780 K?

Thanks for the answer.

I’m not exactly sure what you mean.

You can set hsbk of (0, 0, 1, 5780) to have a white with kelvin of 5780.

Sorry for the confusion. I was wondering if there was a way to make the device ignore the Kelvin value entirely, as the other three parameters are sufficient to choose an output. Just curious; no big deal.

If you have full saturation, then it doesn’t matter what value you set for kelvin.