Just been playing with the Amazon Echo Hub node - great fun (my IoT students will love it).
One thing I've discovered is... if you ask it to set a colour it doesn't know or understand it hangs-up!!!
For example... Alexa, set 'thing' to black.
"Sorry 'thing' isn't responding, please check its network connection."
You can't turn it off by saying "Alexa, turn 'thing' off."
The only thing that seems to get it out of the hung state is to ask it to set itself to a colour it DOES understand.