How would I change a color for random variables?

I want to change the color of a variable in the inspector to red if its null.
That’s actually probably one of the most-useful ideas I’ve ever heard for the Unity inspector. Wow…
I think that today you woudl need a custom inspector to do it, but it almost should be suggested as a “unity needs this” feature!!
With custom PropertyDrawers. See eg Highlight Property Drawer - Simply sets the text/background colour of a field in the inspector. · GitHub