There are multitudes of ways to effectively integrate color into a residential landscape design.
It can done by mixing a wide variety of colors so that each color is no less or no more important than the other. Or color can be arranged so that one color dominates all others by its presence. Color can be subtle. Color can be bold. Color can blend. Color can contrast.
Ultimately, it is incumbent on the designer or landscape architect to understand how they want to most effectively used color in each circumstance. Given all other considerations my preferred method is to have one color dominate the scene for a prolonged period of time, then give way to another color for another prolonged period of time.
The shot below is from Luthy Botanical Gardens http://www.peoriaparks.org/luthy-botanical-garden/ and shows how to let one color dominate all others. In this case the dominating color is the red foliage of a banana plant, but it could just as easily be the bright blooms of a canna.
There are no ‘rights and wrongs’ with color and how to incorporate it into landscape design. The most important thing is to understand how the color will work over the course of the season.