Nature's Black and White

I'm taking a black and white digital photography class, and I never realized how hard it would be to take something that is so pretty in color and change it to black and white. So, I was walking home from this class when I looked up into the sky and I noticed the clouds. They were this beautiful dark gray, with light centers and darker edges and they stood out starkly against the lightness of the sky. I was shocked. Here I was looking up at a perfect example of black and white from something that is normally so colorful and vibrant (or just blue). It made me realize how much variety there is around us in terms of color, and it also made me realize how ever-changing the sky is.