One of the reasons why I moved away from using my Nikon Speedlights was that I was always getting inconsistent colours in the pictures. You would take one frame and without changing anything the colour would be off.
Now that I have a colour meter I can actually see that the flash gun was putting out very different temperatures each time it went off.
As you can see it is not just by a little bit but by a lot.
Doing the same test with the Profoto B10 the temperature was very close to each other. So it wasn’t something that I was doing wrong.
I do wonder if Nikon have now fixed the problem in the latest Speedlights. In reality I probably won’t find out for myself if they have as I don’t have the spare cash to get a unit to test.