Why do devices with 'ColorTemperature' trait in rooms receive commands for 'ColorSpectrum'?

Question

To illustrate an example scenario that prompted this question, please consider the following:

• A room, attic, that contains 3 devices: one light that supports both ColorSpectrum and ColorTemperature, one light that only supports ColorTemperature and one light that only supports ColorSpectrum (all 3 also support OnOff and Brightness, but this appears to be irrelevant).
• "Set the attic to warm white" will result in two of the lights receiving a temperature value in Kelvin, whereas the third (which didn't support ColorTemperature) will receive an rgb/hsv color value approximating the correct hue of white.
• Conversely: "Set the attic to red" will result in all 3 lights receiving an rgb/hsv color value (including the light that does not support the ColorSpectrum trait).

We are unsure how a light that supports only ColorTemperature is supposed to respond to an rgb/hsv value. This final scenario - after the light's failure to be able to execute the user's command - left us with 3 options to respond:

1. Lie and respond 'SUCCESS' for all 3 lights, "Ok, changing 3 lights to red."
2. Omit the third light from the response entirely, "Ok, changing 3 lights to red."
3. Respond with "notSupported" 'ERROR' for the third light, "Ok, changing 2 lights to red. That mode isn't available for the LIGHT_3."

Option 1 is clearly undesirable, incorrect feedback is worse than no feedback at all.

Option 2 is equivalent to 1, though it seems odd that Google Home should assume that a device omitted from a response was successfully processed.

Option 3 we deem unideal as well, as we expect the user may get bored of hearing that a certain light in their room is unable to change color when they might be perfectly aware of this fact. Our preference would go to a response of: "Ok, changing 2 lights to red." We feel that this communicates clearly that one light didn't change, without the potentially superfluous error message.

Our question, then, is how we might realize this?

Is the behavior listed above unintended (a bug)?

Is there some response that we are unaware of that can be used to communicate to Google Home that a device simply is not eligible for the provided execution?

Is the behavior listed above not experienced by others or the result of a mistake on our part?

Thank you for reading.

Answer 1

I'm going to check about this scenario as it might be a bug in which devices get commands when they shouldn't.

Canonically, option three may be undesirable but is the right implementation. Trying to ignore the command will also create a bad user experience as they receive an incorrect reply.