According to Julie Mulligan - certain colors of roses mean different things. Having been around flowers quite a bit in my life, I have also heard those things. But here is what she says:
Red Says Romance
The red rose says, "I love you." A vibrant and dramatic color, it stands for romance and passion. It's the perfect choice for your true love, the love of a lifetime or someone you want to get the message that it's time to get serious.
White Says Innocence
A white rose tells your favorite angel that they're simply "heavenly," and it's a great color choice for the romantic in your life. White roses also stand for innocence, which makes it a perfect color choice for dads to give daughters or sons to their moms.
Pink Says Grace
Send deep pink roses and you're telling that someone special you appreciate their graceful style and gentle nature. Send them light pink roses and you're saying, "I really admire you." This rose color is just the right choice to send to someone with love "from your secret admirer."
Yellow Says Friendship
Bright, sunny yellow roses symbolize friendship, affection and joy. Send your best friend a bunch of these stunning blooms with a card that says, "You'll be my best friend forever."
I'd have to say that I agree with all these colors. That's what I've always heard. And I definitely think I would like to stay away from red roses (roses in general, but definitely red). Although I will admit that I've been given roses of every color. I don't think very many guys understand the color meaning, so I figure from those guys it doesn't mean anything.