A small difference maybe.
Obviously many guys feel the compulsion to keep that virile look going by turning their gray hair to dark via one of the popular men's hair products such as Grecian Formula. It may be partially pride, it may be partially effective marketing strategy, it may be that their wife wants them to.
I would wager that those of us who are going gray would say that we don't care as much about the color as the presence of hair. Especially when you can rock the gray like ol' Gandalf here. Of course, many times going gray and balding go hand-in-hand. Same type of problem. Age related. Cosmetic and superficial really. The average U.S. consumer spent $616 on personal beauty care in 2008, according to data from the Bureau of Labor Statistics. If there was even 100 million 'consumers', that would come to over 60 billion dollars. I know that 'beauty care' covers a lot more than hair coloring, but by comparison, less than 2 billion was spent on all types of cancer research that same year (according to the National Cancer Institute). Gotta have priorities I guess.
Going gray can be a distinguished look. It's also probably the single most visible sign of age. You can be young and fat, but you're not too likely to be young and gray.
Proverbs 16:31 says: Gray hair is a crown of glory; it is gained by living a godly life.
There's also a Greek proverb that goes, 'Gray hair is a sign of age, not wisdom'.