yes dude, "seriusly"... lol. There is plenty similar;
exhibit 1, Corsair ICUE. you can control mother board lighting (20 different motherboard area options) to the temperature of 29 different sensors, in three adjustable steps. see pics.
If you have a Corsair Mouse, you can control the two zones of aRGB on the mouse to show different temperatures. e.g. Mouse is showing me colour coded GPU temps and motherboard is showing colour of CPU temp. I can see motherboard from the corner of my eye.
exhibit 2; EKWB Loop Connect via SMART lighting. controls Fan lighting colours based on temperature sensors. 3 sensors around the loop give coolant temperature. If it goes high, 6 fan lights start flashing.
Two others which may well do a similar job... control the lighting in some way to illustrate temperature, although I've not confirmed this, are the NZXT and Argus monitor. There are probably others too that I dont know about.
So It seems quite common dude!
it cant be that difficult, if you can control a fan speed based on temperature then changing the colour of an LED sounds a lot simpler. There are numerous Arduino controlled Led systems on Github, so its clearly something the modding community are actively embracing.