The Nimbochromis livingstonii dorsal fin (located on the back) may be blue and the males tend to color up and turn a dark blue during breeding.
The dorsal fin may also show blue coloration while maintaining an orange to red band and sometimes a white line. A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Adult males frequently "color up" in response to changing conditions and rapidly change from spotted camouflage to brilliant blues and greens and may even exhibit a pale golden tone. Breeding males turn a dark blue which almost completely obscures their blotched pattern. 
