In Raphael's painting below we can see how by having a clear sense of symmetry adds to the structure of the entire composition. Symmetry and Order refers to the idea of how balance, and symmetry give the composition an overall feeling of solidity and structure.
In general it is a good rule of thumb to think that warm colors will come forward in space while cool colors recede. Also notice how Matisse utilized contrast, as well as color to make the figures come to the front of the painting, and push the background back in space. It is also helpful to think of the ground as the negative space around the figures present. In the Matisse painting below we can see a clear differentiation between figure and ground. These differences can be furthered by utilizing a number of different techniques which can include contrast, color, intensity, and size. This is the idea that speaks to the human mind's tendency to separate figures from their backgrounds. The main points of Gestalt are summarized below the image. It is often used in both art as well as design to achieve the desired effect.
These theories of painting come from a German form of psychology called Gestalt which simply states that the whole is greater than the sum of its parts.
