Alexa not sending the correct color codes

[Perforex]

I'm implementing a device that is using MQTT to control some multi coloured LED lights via a microprocessor. When I change the light colour from the "Test Color" button on the Devices screen all is well and the correct 6 character hex code is sent to the MQTT queue. However, when I do the same from Alexa I get a spurious code, usually x"FDFDFF" but sometimes a slight variant.

Here's the MQTT string from the device:

{"clientId":"hab001","topic":"home/colour/test","message":${color.rgbx},"qos":"1","retain":"false"}

[amoksworld]

Same problem here ...

I use a HTTP call with ${color.rgbx} and when I test color from habridge web interface it is working correctely:

http:https://127.0.0.1/fhem?cmd=set%20Light%20rgb%20${color.rgbx}

But when I ask Alexa to change the color, the resulting HEX code is wrong.

I also tested with ${color.rx}${color.gx}${color.bx} instead and got the same result.
Even with another API call that includes ${color.r}${color.g}${color.b} the colors are mixed.

http:https://127.0.0.1/fhem?cmd=set%20Light%20wcrgb%200%200%20${color.r}%20${color.g}%20${color.b}

But I get reproduceable responses ... so I did a little bit of debugging...
First thing: It seems that changing the luminance in habridge (or with alexa) has an impact on the calculation, because when I set different luminance values the RGB/RGBX code change.
When set lumination to high and ask Alexa to set a color, she says something like "value out of scope"
Second I noticed, that when I say "blue" and expect that the last 2 of the 6 HEX chars change, they are set to 00. If I play with the luminance, I see the first 4 HEX chars changing, but the last 2 stay at 00 what seems to be wrong to me.

Hope someone can find the error and fix that little thing.

[bwssytems]

Also an issue with #1132