One of the reasons I don't do color or paint.
I'd say she is right. Color is tricky business. Look at how painters or museums mat their paintings. Go to a frame shop and talk to a framer. Color helps convey mood and emotion. So I suppose it depends on what you are trying to do and who your audience is. Remember that 12 to 20% of white males are 'color blind'. Also remember, if it didn't make a difference then businesses wouldn't pay color consultants millions of dollars to pick colors for hospitals and restaurants, etc. Everything makes a difference.
One reference is the book: The Elements of Color, by Johannes Itten