Donna, I have done that so many times -- had to tell a man I'm dating about my hair. I write about it at length in my book. Every instance is different. I go by feel and usually I can pick exactly the right time to do it. I don't make a big deal out of it, and 90% of the time the guy is great. Sometimes, though, you get dumped. But who wants a guy like that, anyway? It separates the men from the boys. 

Yes, I understand. It's natural. You are not alone. Let me know if I can help or answer any questions...

Good luck! And don't worry, you have a lot of support here!