Ok i have never kept african cichlids but as i was lookin through my practical fishkeeping magazine i spotted a fish just like yours (but more red and blue)
It was described as Aulonocara sp. "Eureka" or just eureka.
It also said they get 15cm and is a man-made selectively bred form of Aulonocara jacobfriebergi (what a mouthful) and don't ask me what that is??