For the month of June the card swap group worked with Analogous Colors.
Analogous colors are groups of colors that are adjacent to
each other on the color wheel, with one being the dominant color, which
tends to be a primary or secondary color, and two on either side complimenting, which tend to be tertiary.
The term analogous refers to the having analogy, or corresponding to
something in particular. An analogous color scheme creates a rich, monochromatic look.
Here is an example of analogous colors.