Primary Colors represent Integral Colors, which means the color that gets mixed in with the concrete.
Secondary Colors represent Release Colors, These are commonly referred to as Antique Colors.
Secondary colors are only used during the stamping process so if you are not stamping then you will only choose from the Primary Chart.
Concrete colors and charts are only a representation of a certain amount of color per batch. There are many variables when it comes to final color. Materials, ratios, and other factors affect final color. Your curb may be slightly different that what you see here.