I've probably done less than 10 in my whole life. However, back in the day before polytranspar and color charts I would research a fish if painting for the first time. Mostly photos from hunting and fishing magazines. Also, I'd study the dead, iced down fish , and with that and the color pics. I would try to get it close. I don't have access to live , fresh out of the water trout. SO.....what color do you paint the upper back on a rainbow trout? If you can, give a "oneword" answer please. Black, yellow, red, blue, brown, purple, green, etc. Just for fun. I just watched a dvd by an expert. Either I'm colorblind or he is, I've been getting it wrong all this time. lol!