Yes, I know--I'm a little bit crazy. I look at nature and see color--glorious color--and give it a DMC name. For instance, this photo of my perennial garden--just starting to come to life--I look at my forget-me-nots at nine o'clock and think--DMC #3840.
A couple of days ago, my local needlework group had its annual luncheon. It was a gorgeous Cape day, and as we left to drive home, I looked at the sky. "A DMC #334 sky!" I remarked, and my needlepointer friend who had walked out with me laughed. She knew exactly what I was thinking.
Poor DH is used to it. When we're out and about, doing errands or whatever, we often pass bodies of water. I'll say, "Wow, it's a DMC #336 today!" as we go by Crystal Lake. In winter, more often, it's a DMC #415.
A couple of years ago, someone on the ANG discussion list asked about the correct DMC number to stitch water for Cape Cod Bay. I was actually still living in Texas then, and felt a bit reluctant to answer her question. The answer, really, is simple: look at the sky.
Different parts of the country have different shades of blue in the sky. Florida has a slightly green cast to its sky; the Cape has a tinge of gray. Look at your DMC color card--a must for figuring out color families--and find your sky color. Scale down to a darker shade and--voila!--you have the shade you need for the water. Of course the shades vary with the seasons, but you get the idea!