All of these are a part of Light. The first on Black and White I took on a cloudy day at Lilac Circle I used Camera Raw to turn it black and white.
The second one Complementary Colors I took a picture of this Because it was of complementary colors. Plus it was close to Christmas when I took this photo.
The third one is Monochromatic Color. I took it at the same place as the first one. Plus the leaves were around that time of the year where the colors of the leaves could blend in with the wood of the tree.
Light
Black and White
complementary Colors
Monochromatic Color