Can I make an editor widget that accepts drag and drop operations from the rest of the unreal editor?

Sorry if this is a dumb question - couldn’t find anything with a search. I want to write a custom editor widget with color boxes in it that I can drag and drop colors into (from the normal unreal engine editor color picker, or from existing color boxes – in the details panel of a light or material instance for example),

and similarly, that I can drag colors out of (into the main color picker or light details, etc.).

Is this something that’s easy to implement with editor widgets without breaking out the C++?