Using daylight white balance at dawn and dusk produces bluish pictures. Rather than adjust the white balance, which takes time away from focusing on a composition, I allow the pictures to go blue because, often, I like the results. If I don't, I use the 'temperature slider' in Adobe Camera Raw (or Lightroom) to tweak the color in the image to warm it up. I photographed this hoarfrost-covered tree at dawn in the Grand Tetons National Park and decided the blue color cast made this especially beautiful. Photography doesn't have to capture what you see. It certainly can, but it's not a requirement. That's why I like to manipulate images so much. I create pictures that I see in my mind and not necessarily through the viewfinder. My settings for this shot were 1/200, f/9, 1600 ISO, and I used a 100-400mm Canon zoom.