They are powerful and yet calming. The vibrant color willoverpower the pastel is used in equal proportions. Vibrant accents create a nice balance in a pastel scheme. Analogous colors are separated by one color on the wheel. These colors create continuity as they share a common color.
Adjacent colors are side by side on the colorwheel.
These colors harmonize and blend together. Mint green with an accent of bright blue can work well for water scenes. Use the middle color as the predominant color and the other colors for accents. Different shades have more of certain colors than others. Terra cotta is a very orangey brown, mustard brown would have more orange and yellow.