What I will never understand is that most devices are designed by males, and a high percentage of males are colour blind to some degree.
And given that red/green is the most common form of colour blindness, what the hell is with all the devices that use dual colour r/g LEDs, like battery chargers? Often I can't tell the difference, if there are some red and some green I can see that they are different to each other and deduce which is which because some are "redder" than the others. But if they are all the same I've nothing to compare with and I have a hell of a time.
What's wrong with flashing to differentiate? Everyone can tell the difference between a flashing LED and a non-flashing LED.
Rob