Attach narrow wooden strips to each compartment on the front, these serve as a stop for the Plexiglas plates
Drill the extinguisher for wiring
Connect E27 lamp sockets and screw one into each compartment (in the middle of the rear third)
Smart Wifi RGB LED bulbs screw into the sockets
Supply bulbs with electricity
install and start the APP for the RGB bulbs (in my case iO.e, this one works with IFTTT, to control the color and brightness)
Turn each bulb off and on 3 times, it should start flashing. After that, connect the bulb into your domestic network via the app. Each bulb should get a unique name (e.g. CO2, humidity, temperature).
set up IFTTT, here is an example: If Temperature rises above 23 Celsius, then set RGB Temperature color to Orange and brightness to 100%
set up the IFTTT applets below
Cut Plexiglas plates so that they fit into the boxes and attach to the wooden strips
attach stickers on the Plexiglas plates (I've order them at klebefisch.de mirror-inverted and attached them on the inside), Download example icons
Fix plexiglass plates with hot glue
Finally, I have the whole shelf yet slid with natural paper, for a nicer finish
Hints
Costs: ca. 120 € Time required: about 3-4h
I have tested some RGB lamps from far East. For example, Sonoff with the eWelink app and various bulbs with the SmartLife app. The Sonoff from iTead is not supported by IFTTT. Although devices in the SmartLife APP should be able to be controlled via IFTTT, but I could not select the RGB bulbs in IFTTT. I have successfully tested the Philips Hue System and RGB bulbs that are compatible with the following APPs: iO.e & Magic Home
IFTTT
If Temperature rises above 24 Celsius, then set RGB-Bulb-4-Temperature color to Red and brightness to 100%
If Temperature drops below 25 Celsius, then set RGB-Bulb-4-Temperature color to Orange and brightness to 100%
If Temperature rises above 23 Celsius, then set RGB-Bulb-4-Temperature color to Orange and brightness to 100%
If Temperature drops below 24 Celsius, then set RGB-Bulb-4-Temperature color to Yellow and brightness to 100%
If Temperature rises above 22 Celsius, then set RGB-Bulb-4-Temperature color to Yellow and brightness to 100%
If Temperature drops below 23 Celsius, then set RGB-Bulb-4-Temperature color to Green and brightness to 100%
If Temperature rises above 20 Celsius, then set RGB-Bulb-4-Temperature color to Green and brightness to 100%
If Temperature rises above 18 Celsius, then set RGB-Bulb-4-Temperature color to Cyan and brightness to 100%
If Temperature drops below 21 Celsius, then set RGB-Bulb-4-Temperature color to Cyan and brightness to 100%
If Temperature drops below 19 Celsius, then set RGB-Bulb-4-Temperature color to Blue and brightness to 100%
If humidity rises above 65%, then set RGB-Bulb-4-Humidity color to Blue and brightness to 100%
If humidity drops below 65%, then set RGB-Bulb-4-Humidity color to Cyan and brightness to 100%
If humidity rises above 60%, then set RGB-Bulb-4-Humidity color to Cyan and brightness to 100%
If humidity drops below 60%, then set RGB-Bulb-4-Humidity color to Green and brightness to 100%
If humidity rises above 40%, then set RGB-Bulb-4-Humidity color to Green and brightness to 100%
If humidity drops below 40%, then set RGB-Bulb-4-Humidity color to Yellow and brightness to 100%
If humidity rises above 35%, then set RGB-Bulb-4-Humidity color to Yellow and brightness to 100%
If humidity drops below 35%, then set RGB-Bulb-4-Humidity color to Orange and brightness to 100%
If humidity rises above 30%, then set RGB-Bulb-4-Humidity color to Orange and brightness to 100%
If humidity drops below 30%, then set RGB-Bulb-4-Humidity color to Red and brightness to 100%
If carbon dioxide drops below 1000 ppm, then set RGB-Bulb-4-CO2 color to Green and brightness to 100%
If carbon dioxide drops below 1200 ppm, then set RGB-Bulb-4-CO2 color to Yellow and brightness to 100%
If carbon dioxide rises above 1000 ppm, then set RGB-Bulb-4-CO2 color to Yellow and brightness to 100%
If carbon dioxide drops below 1400 ppm, then set RGB-Bulb-4-CO2 color to Orange and brightness to 100%
If carbon dioxide rises above 1200 ppm, then set RGB-Bulb-4-CO2 color to Orange and brightness to 100%
If carbon dioxide rises above 1400 ppm, then set RGB-Bulb-4-CO2 color to Red and brightness to 100%