protanopia: can't see red. protanomly: some red is visible. The guy I worked with who was RG CB couldn't wire up stepper motors (typically use 4 wires, red gr

protanopia: can't see red. protanomly: some red is visible. The guy I worked with who was RG CB couldn't wire up stepper motors (typically use 4 wires, red green blue black), he couldn't tell the difference and had to use a multimeter.