This was about sRGB color space and linear color space! down here I will put more useful resources, which you can read them!

https://learnopengl.com/AdvancedLigh...
https://www.cambridgeincolour.com/tut...
https://blog.johnnovak.net/2016/09/21...
http://blog.wolfire.com/2010/02/Gamma...



Also I add one more thing here, Many game setting contain a setting for changing gamma, that is another gamma which apply on top of all this!
If you want to add this functionality in your Godot game you can change the value of gamma in Environment node! also you can let player change that by adding some code


Video Chapters:
intro 00:00
History & Concept behind this 00:19
Math formula 02:20
today LCD 02:40
Benefit of storing in sRGB 03:14
sRGB in computer graphic 05:26
convert sRGB to linear 06:45