Ruler designer - no hair colour change

[tapewormlondon]

When designing a ruler you can only choose black hair. All numbered options the same

 

[Servancour]

I tried swapping the colour of a few different portraits and the colour was changed correctly. Are you trying on a specific portrait pack? Does it happen on every character?
Remember to include version number and checksum when writing bug reports in order to make it easier for us. You could try to verify your files to see if it's an issue there.