The evening's presentation was a lecture on Composition. During the discussion, we covered ten methods I find necessary for creating a center of interest in a composition. They can be found in my book "Principles and Techniques for Drawing and Painting".
As I prompted the group for ideas, one member suggested complementary colors as a possible method. Initially I thought that I might have to add that to the list! However, after some thought and experimentation, I found that it actually comes under one of the existing ten methods.
Red and green are complementary colors, but because they are used equally, no one square is more important than another.
The second set of squares has just one red square, which is more important, not because it is a complementary color but because it is unique, which is one of my existing ten methods.
Even though the wading bird is very small, it is the center of interest because of animation–living things (people, animals) are of more interest, and will always capture our attention first.