That's what they said about Gorgeous George, Randy Savage, Ric Flair, Hulk Hogan et al, but I don't thik it was true.

Not really, I dyed my hair just because I got bored.   Its blue  ^.^

Maybe people just want to do everything they can to look nice. Doesn't mean you're vain just because you want to take care of yourself.

I've had some grey hairs since I was about 26, and I know folks that had them way earlier than that. does that make me vain not wanting other people to see them and judge me?

Some, maybe.  Others may be insecure about their appearance. Others may have recently had their hearts broken and are looking to change their lives as much as possible to start over.  Others might be trying to hide their grey hairs out of fear and shame of "looking old".  I met a lot of women who fall under all these categories and then some.

I should compliment my sister when I see her!

This can be true of some. But then again, there are many people that do it because simply want a little change.