Here is an example of a small segment of the color wheel being used as an analogous scheme. If it didn't span from yellow-green to blue-green, it would almost come across as monochromatic. If you're interested in testing yourself on picking out the obvious and the more subtle hues, tints, and shades in an analogous scheme, the following examples are unlabeled.
Chroma Many color wheels include the dimension of grayness versus intensity, known as chroma, also commonly called saturation. Here’s the traditional artist’s color wheel I made years ago, which goes to zero chroma at the center.