the safe key i need to find is for the museum of technology and what do the red and blue pass cards do

Red and blue keycards are clutter, they don't have any use. As for the safe key, you need to access several terminals and follow a certain sequence.
It's been a while so I hope someone else can be of more use to you. Save before you try, or you might get locked out!

http://fallout.wikia.com/wiki/Jiggs%27_Loot

That's the one, good luck! Reward's one of the best guns in Fallout 3!