Not sure if this is relevant or not, but scrilloing down on that article you can learn something new everyday......
Blue buttocks The lesulas live in this isolated region in groups up to five strong, and feeds on fruit and leafy plants. The males weigh up to 15 pounds (7 kilograms), about twice the size of the females. They also have some rather arresting anatomical features.
"They have giant blue backsides," Hart said. "Bright aquamarine buttocks and testicles. What a signal! That aquamarine blue is really a bright color in forest understory." 