What the edges are. No cold edge published. Warm edge: 60-day upper lethal; feeding ceases approaching 68 °F. These are not one consistent quantity across species. A measured avoidance temperature is where fish were seen leaving; a water-quality maximum is a regulatory ceiling written to prevent a kill, and it sits well above the point a day gets difficult.
Source. Bear, E.A., T.E. McMahon & A.V. Zale 2007, Comparative Thermal Requirements of Westslope Cutthroat Trout and Rainbow Trout, Transactions of the American Fisheries Society 136:1113–1121. Read it.
Warmwater species swing their preference ten degrees or more between winter and summer in the same laboratory. One band per species is a summer simplification, and it is why the drawing shows a band rather than a line.