Tradfri Color Temperature Range Incorrect?

Configuration Zigbee
1

I just paired my new Ikea Tradfri bulb with Home Assistant via ZHA. I see that the color temperature option ranges from 2202K-4000K in the HA interface. But, I bought these bulbs because they have a wide color temperature range.

The manual says

With the remote control you can switch
between 9 colours and white lights:

White tones
Cool white - 4000 Kelvin
Warm white - 2700 Kelvin
Warm glow - 2200 Kelvin
Candle light - 1780 Kelvin

Colours
Amber, Dark peach, Dark pink, Light
purple, Light blue

If you add the gateway and the app,
you get a total of 20 colours and white
lights:

White tones
Cold sky - 6000 Kelvin
Cool daylight - 5000 Kelvin
Cool white - 4000 Kelvin
Sunrise - 3000 Kelvin
Warm white - 2700 Kelvin
Warm glow - 2200 Kelvin
Candle light - 1780 Kelvin

Colours
Amber, Peach, Dark peach, Dark red,
Pink, Light pink, Dark pink, Light purple,
Dark purple, Blue, Light blue, Lime,
Yellow

So, a range of 1780K-6000K seems possible? Why isn’t that available with HA? I don’t have any Ikea hub.

Details:
TRADFRI bulb E26 CWS 800lm (LED1924G9)
Firmware: 0x10021655
Zigbee dongle: SONOFF Zigbee 3.0 USB Dongle Plus Gateway (ZBdongle-P)

Any help appreciated, thanks.

2

To my knowledge Tradfri bulb has 2 LED modules (in one bulb):

  • CCT LED module that supports 2200 - 4000 kelvin range
  • RGB LED module that has full RGB spectrum

So in range of 2200-4000K the bulb uses its CCT module (which is more color-accurate), while for the rest it uses RGB module. I assume Ikea’s hub has a lookup table of sorts, for example:

  • Cool sky - RGB(255,255,255)
  • Cool daylight - RGB(255,240,240)
  • Cool white - CCT(4000K)
    etc.

So, technically you can replicate the same behavior by finding which commands the Ikea hub sends and setting up buttons for those “special” out-of-range colors. Or you can manually find which RGB color roughly matches the required color temp.