Here is one that is not very scientific-
http://carolinefernandesgoldfish.blogspot.com/2012/08/blog-post.html
and one that is (sorry no link)-
Effects of background color on growth performances and physiological responses of scaled carp (Cyprinus carpio L.) reared in a closed circulated system
S.E. Papoutsoglou a,* , G. Mylonakis a, H. Miliou a,
N.P. Karakatsouli a, S. Chadio b
Too funny...
thx