Colour grading is subjective at the best of times, and flawed most of the time. Unless both you, and the viewer, have an identically calibrated monitor nobody is seeing what you think you created.
Why aren’t all display screens and monitors calibrated to an internationally agreed standard at the factory?
How hard can it be?! 
They vary with usage and time in any case.
Differing tech, too. Bit-depth, LED types. HDR/SDR.
Now out of Beta = New thread : Davinci Resolve - v19 is out of Beta