Have you ever knocked out a guard and gone OH DANG IT the key i want is not there?
Well i will tell you how to get the key you want from what guard.
Ok first thing when you make a new game file as in choose what prison it will come up with the option that you can name your inmates or officers. Well rename the first officer Yellow Key as for he has the cell key The second guard has the Orange Key The Third guard has the Purple Key and the fourth has the Red Key and the fifth has the Green key.
I hope this helped.