Subtle edits to Curie's facial features to make her better suit her innocent and good-natured personality.               
The vanilla face is very sharp featured, with a broad jaw, large chin, and small shrewd eyes. None of these features reflect Curie, and that's fine, since it is after all, the body of a pre-existing synth character.                            
Despite that logic, there was always a disconnect for me between the way Curie acts/talks, and the way she looks.        
Even moreso is the bright colours and overall roundness of her original robot frame, which you tend to get used to. I think Subtle Curie is a more natural evolution of that original look.                                   
That said, I aimed to stick close enough to the original face that she's still recognizable as Curie, as opposed to changing her into a completely different person.                        

Q: Why the hair colour change?   
A: I felt the swarthy dark look vanilla Curie had didn't feel like a natural progression from her original Mrs. Handy, and that this suited her better.             
Luckily, if you have a preference for a dark haired Curie, I uploaded a Dark version of the Subtle Curie Edits


Other Subtle Character Edits:
Subtle Preston
Subtle Macready
Subtle Mama Murphy
Subtle Skinny Malone

Other Face Edits: 
Mama Murphy Concept Art
Hancock Edit