Take the time to research the different retaining wall block colors. A wide choice of colors are available that range from tan, brown and gray to red, blue, green and mauve. There are also blends and marble choices.
Go to the building supply store and get retaining wall block color samples. Place the sample in the landscape to get an idea of how the color looks. Don't rely on pictures to give you the true color.
Select the color that matches the materials and plants of the surrounding area. Consider the color of the house brick, the roof, the patio pavers and the pool deck when making a choice.
Blend the wall block colors or create a contrast. Matching the roof will offer one way to get a contrast to the house.
Make the wall block color match the architecture of your home. There is a color that matches and complements your home, whether it is modern or classic.