Material node preview.

I think I have a problem here in live nodes, white color appears as a red color unless I start previewing the material.

I also get red. It probably means something deep, I have no idea what…

Works fine if you actually plug it into the material node:

Yes, I know, but sometimes I have to unplug the others to see the changes.
Could you please multiply it by one and show me the result in node preview?

This is a regular behaviour inside UE since UE4.
What I am aware of is that it is mostly due to it letting you know that it is a float and not a vector. When ever a float is used, it is implicit that the X channel (R) is being used, therefor, being shown as red.

That’s what I’ve read, but if some one has something different, would be great to hear!