Open PM (Vista 64)
Open a Contact Sheet of untouched (or new) images.
Tag a few.
Change the color label of a few tagged images as well as untagged images.
The Tagged images (in my case) will not have the Color Label applied in NX2.
Once the tag has been changed, I am not able to ever change or apply a color label from PM in NX2.
If you can't repeat this, let me know and I will do it with a video (I can repeat it every time)