If you want to skip the details, I've created an infographic guide for consistent color from DaVinci Resolve to QuickTime to YouTube and Vimeo with QuickTime Tags. In it, I describe project settings, monitoring options and export settings from Resolve to maintain expected color through delivery.
Matching Color: DaVinci Resolve’s Viewer & Mac P3 Displays and Applications (for macOS High Sierra)
The information in this article has been updated in this latest article about best practices for color shifts in Resolve and later versions of Mac OS: https://www.thepostprocess.com/2020/07/17/color-on-mac-displays-from-davinci-resolve-to-the-internet-with-quicktime-tags/ For an in-depth analysis