Why does hot water still come in my washer when I have it set for cold?

There is a short somewhere between the wires on the solenoids. You will have to trace it with an ohm meter with unit unplugged.

What drtom said or even a bad switch. The selecter switch send power to either/or/both water fill solenoids. A short could power both or a bad swicth. What happens if you close the hot valve coming to the washer?

What ballengerb1 said is a good point. There is the switch that chooses the water temperature located next to the timer. One hot wire goes in from timer and two wires go out: One to the hot water valve and one to the cold water valve. If there is a short in that switch it would send power to both valves when water is called for. You can find where the wires going to the valves plug onto the switch and using an ohm meter see if there is a short: Put the switch on "Cold" and if the two terminals read around zero on ohms then the switch is shorted and you need a new one. If you read around zero when checking between the two wires you unplugged then the short is somewhere else between that point and where they plug into the valves. My money would be on the water temp switch.