Color change, bleaching in Koi

Reader:
Do you happen to know what causes color “bleaching” in koi? Colors become much more muted and washed out. No other behavioral differences 
Dr Johnson: 
 Five things 1) diet that lacks color enhancers 
2) lack of intense sun 
3) living on pale background and substrate 
4) extreme stress 
5) wretched genetics

Author: admin