Not sure this is relevant, but my device handler program is 124 lines long. Is yours? Are you sure you copied and pasted all of the program? I had to copy twice to catch the first two lines.
Make sure to pick the correct handler in IDE when setting up device. However, seems odd to me the “Name” and “Device Network ID” are the the same.
In my “Current States”, Switch on & Level are shown, but no Hue or Saturation are shown. Maybe ESP and SmartThings don’t communicate that or Color.
Whether important or not, I’m using the old version of SmartThings to add device and control the ESP8266 nodemcu WLED device.
In the SmartThings window there is on/off, level control 0 to 255 and a color wheel. All three work, except the brightness of LEDs top out at 100. I’m running a strip of 144 LEDs powered by a 5volt phone charger. So maybe under powered and not capable of 255 brightness level. May also be limited by the WLED program to 100.
Alexa can turn ESP on/off and change color, if basic RED, BLUE, GREEN, YELLOW, Etc commands. Brightness levels do not work. I think because the device’s name is too long and Alexa doesn’t wait for a full command.
If powered off and then powered on, the WLED/ESP defaults to two 72 LED segments running a forward effect and reverse effect. SmartThings can take over no problem. Using color wheel and brightness scale, you can pick color and brightness. Turn on and off no problem.
I created simple WebCORE piston and it controlled on/off, hue, sat, level. However, these changes do not show in SmartThings window. More experiments needed.