Hi,
here is the the promised review about Xiaomi Yeelight RGBW E27 Smart LED Bulb.
The bulb has standard E27 socket.
I personally don’t have E27 bulbs except some movable lamp that I use as additional desktop light so I tested it there.
Xiaomi Yeelight RGBW E27 Smart LED Bulb is a great addition to Xiaomi Yeelight Series, which enhances the lighting experience of your daily life. It features 16 million colors RGB light and 1700-6500K adjustable white light, offering you the most wonderful ambient lighting. With WiFi technology, you can control your light from your bedroom to your backyard. What’s more, is has a ultra long lifetime of up to 11 years.
I download Yeelight app from Google Play and installed.
After start I found the bulb inside app and added it.
There is few options in the app:
- Hue
- White
- Flow
- Scenes
In Hue you can change the light color up to 16mil colors.
Also you can change the brightness.
Unfortunately it’s not possible to lower down the brightness as low as i wanted.
So for my needs – baby room sleep light it’s not usable.
Anyway in White mode as the title says you can use only white color and change only brightness but again cannot be lower much down.
In Flow mode the light changes color automatically.
The next mode is Scenes – probably the most interesting.
Inside there is few ready to use scenes.
Most interesting is Sunset and Sunrise.
They simulate Sunset and Sunrise for 10min.
You can add own scenes too.
In conclusion I can say this bulb is good for child or teenager room or some eccentric people 
But personally I’d chose some RGB LED strip instead of bulb.
Anyway if you like it you can buy it from HERE