Kyle M. answered  10/25/15
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We know that "not one of them" is wearing the color of hat matching their name & that Ms. Red answered the lady wearing the blue hat. This should narrow it down for us - if we assume Ms. Red was not answering herself!
Ms. Red is not wearing blue or red, so she must be wearing white. This leaves Ms. Blue & Ms. White, neither of whom could be wearing the same color as their name.
As only the blue & red hats remain, Ms. White must wear a blue hat & Ms. Blue wears a red hat.
 
     
             
 
                     
                    