I sold a business shirt. A white business shirt. 

I've just gotten a message complaining that the shirt is the wrong SHADE of white! Her idea of white is the crisp white, the one with a slight blue tint. The shirt was flat white (she is calling it cream).

Am I really supposed to just refund money because she wanted a different shade of white? 

This is the second one this week that, as far as I can tell, is angling for a partial refund/discount. This is getting ridiculous.