This pattern alternates two different orientations of pentagons. The pointing up ones are blue and the pointing down ones are purple. Notice that all but one of the pentagons (the central pentagon) are connected to exactly three other pentagons. The pattern can be thought of as concentric rings of pentagons (that will approximate decagons). Another way to understand the pattern is by grouping rhombi (the white diamond slivers) in terms of orientation--there are five different orientations. The rhombi form ten wedges that meet at the central pentagon.