Just as a presentation has an assortment of themes available to give it its overall look, each layout for a SmartArt graphic has a range of styles available to it.
There is a default style applied to the graphic when it's first inserted, but you can choose a different one. For example, the picture shows the same graphic you saw previously, with the Office Theme still applied to the slide — but now a different style is applied to the graphic. The earlier style, called Simple Fill, is replaced by one called Intense Effect.
The new style keeps within the basic color range of the default theme, but now the big shapes are rounded, or beveled, at the edges, and they have a shiny highlight at the top. Look closely to see the reflection added at the bottom.
Also, the long shapes holding the secondary text have a highlight at the far right, and a shadow at the bottom, giving them dimension.