A Unity sample project applying a LUT (.cube file exported from DaVinci Resolve) with Shader Graph.

• Take a screenshot in Unity for grading.
• Create a new project in DaVinci Resolve.
• Change the Color Management settings in the project settings:
  • Color science: DaVinci YRGB Color Managed
  • Color processing mode: SDR Rec.709
  • Output color space: sRGB
• Import the screenshot and change the Input Color Space to sRGB.
• Grade it in the Color page.
• Generate LUT (right click menu on the clip) - 17/33/65 Point Cube

Now you can import the .cube file by simply drag-and-drop into Unity Editor.

They're useful for grading the render output from Unity. I use the LUT approach for grading a camera input (e.g. webcam).

Because I use it with the camera input. It would be Rec.709 or sRGB.