RGB controls displayed for IKEA Kajplats bulb with white spectrum

[Solmath]

The problem

I just got some Kajplats bulbs from IKEA's new Matter line-up. For one of these bulbs, the KAJPLATS E27 WS globe 1055lm (LED2407G8), the light settings allow to set the color, although RGB is not supported by the device.

The difference to the other Kajplats bulbs I have seems to be that this one has supported_color_modes: color_temp, xy, while the others only have color_temp.

A check in the Matter Server UI revealed that the device in question exposes the CurrentX and CurrentY attributes in the ColorControl cluster in addition to what I can see for the other bulbs.

I'm not sure if this is something that can be solved on Home Assistant side or if it is an issue that needs to be fixed by IKEA.

What version of Home Assistant Core has the issue?

core-2026.1.3

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

Matter

Link to integration documentation on our website

https://www.home-assistant.io/integrations/matter/

Diagnostics information

matter-01JS5CJ989T7W78950WGDYT2D0-KAJPLATS E27 WS globe 1055lm-ff950d83e533104e213aa12d1bdc0749.json

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

No response

[home-assistant]

Hey there @home-assistant/matter, mind taking a look at this issue as it has been labeled with an integration (matter) you are listed as a code owner for? Thanks!

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@Solmath Thanks for reporting this issue!

Before we dive in, please make sure this isn't a duplicate by searching through existing issues. Also check recently closed issues, as your problem might already be fixed but not yet released.

https://github.com/home-assistant/core/issues?q=%20label%3A%22integration%3A%20matter%22%20
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[baldmaniac]

this is also an issue with the KAJPLATS GU10 WS 575lm (https://www.ikea.com/se/sv/p/kajplats-led-ljuskaella-gu10-575-lumen-smart-vitt-spektrum-50611442/) which is supposed to be a white ambiance bulb as well.

[salasami]

I can confirm this also. I have a "KAJPLATS E27 WS G95 clear 806lm" and a "KAJPLATS E27 806lm 95mm smart WS", both similar lamps, even though they announce themselves with slightly different names.

In Home Assistant’s Matter diagnostics, on Endpoint 1 / ColorControl (cluster 0x0300 / 768) both devices report:

ColorCapabilities (0x400A / 16394) = 24 (0x0018)
FeatureMap (0xFFFC / 65532) = 24 (0x0018)

That corresponds to XY (0x0008) + ColorTemperature (0x0010) being advertised, even though in practice the lamps only support color temperature.

Sanitized excerpt (only the relevant cluster attributes, everything else omitted/redacted):

{
  "endpoint": 1,
  "cluster": "ColorControl (0x0300)",
  "attributes": {
    "ColorCapabilities (0x400A)": 24,
    "FeatureMap (0xFFFC)": 24,
    "ColorTemperatureMireds (0x400B)": 153,
    "ColorTempPhysicalMinMireds (0x400C)": 153,
    "ColorTempPhysicalMaxMireds (0x400D)": 454,
    "CurrentX (0x0003)": 9240,
    "CurrentY (0x0004)": 3473
  }
}

(Values above are from the HA diagnostics downloads for both bulbs.)

[DonkeeeyKong]

This is also an issue for the KAJPLATS E14 WS globe 806lm.

[janzziii]

The same with KAJPLATS E27 WS globe 1521lm

[Solmath]

I can confirm this also. I have a "KAJPLATS E27 WS G95 clear 806lm" and a "KAJPLATS E27 806lm 95mm smart WS", both similar lamps, even though they announce themselves with slightly different names.

That's weird, the "KAJPLATS E27 WS G95 clear 806lm" is working correctly for me. I'm on firmware 1.1.0, Hardware P2.0

[rogervdh]

Today some KAJPLATS GU10 WS 575lm (Firmware: 1.2.0 / Hardware: P2.0) spots installed and all recognized as RGB instead of white ambiance.

[mocelet]

It's on IKEA but could be a feature instead of a bug. If you pick a colour it will use the most similar colour temperature it has, for instance red is warm and blue is cool. That seems to be on purpose to have a unified control for colour and non-colour lights. In some cases can be helpful, for instance, a button that could cycle colours in the colour bulb would cycle colour temperatures in the non-colour bulb with the same Matter commands.

Edit: typo

[Solmath]

After switching the Matter server to the beta versions all of my Kajplats white spectrum bulbs exhibit the described behavior. I assume the one that seemed to be fine before was just not properly paired.

With that in mind and considering the previous comment that it might actually be a feature, I guess it's safe to close the issue.

[DonkeeeyKong]

After switching the Matter server to the beta versions all of my Kajplats white spectrum bulbs exhibit the described behavior. I assume the one that seemed to be fine before was just not properly paired.

With that in mind and considering the previous comment that it might actually be a feature, I guess it's safe to close the issue.

How can this possibly be a feature? It's clearly a bug. No white spectrum bulb I own shows RGB controls - and rightly so: They can't show RGB colors. Please reopen the bug.

[DonkeeeyKong]

It's on IKEA but could be a feature instead of a bug. If you pick a colour it will use the most similar colour temperature it has, for instance red is warm and blue is cool. That seems to be on purpose to have a unified control for colour and non-colour lights. In some cases can be helpful, for instance, a button that could cycle colours in the colour bulb would cycle colour temperatures in the non-colour bulb with the same Matter commands.

Edit: typo

If you add non color and color lights to a group, that's the expected behavior. In this case you have RGB controls for the group and the non RGB lights behave as you describe.

It makes absolutely no sense to provide these controls for non-RGB lights outside such groups. It's clearly a bug.

[Solmath]

Even if it is a bug, it's most likely not on Home Assistant.

The IKEA bulbs do actually expose color attributes, which causes Home Assistant to display the corresponding control elements.

I would recommend to open a support ticket with IKEA to make them aware of the situation.

[Solmath]

I contacted IKEA support about the Kajplats white spectrum bulbs incorrectly exposing color controls. The IKEA agent confirmed the root cause:

"the bulbs expose certain attributes (such as CurrentX and CurrentY in the ColorControl cluster) through the Matter integration. This causes your smart home system to interpret these attributes as color-capable, even though the bulbs only support white spectrum adjustment (warm to cool light) and no RGB color changes."

When I pointed out that other manufacturers do not expose these attributes, the agent clarified:

"It is not a feature, but the lamps remain limited to white spectrum control, and the color sliders can safely be ignored."

I requested a firmware fix to remove these attributes since they serve no functional purpose for these bulbs. The agent acknowledged this is technically feasible:

"In principle, this could be fixed by a firmware update that suppresses or hides unsupported attributes. Currently, IKEA's firmware does not filter these out."

"Technically, it would be possible to implement this through a firmware update."

The agent stated the feedback has been documented as a potential improvement, but could not confirm if or when such a firmware update would be released.

I would recommend to reach out to IKEA to get some pressure on this topic.