The Portal Gun is the primary and only weapon used by Chell in Portal. When you first get the Portal Gun, you are only able to shoot out a blue portal. After so many Test Chambers the orange portal is unlocked to be shot.
 Unlocking The Orange Portal Early
If you wish to unlock the orange portal earlier in the game, open up the developers console and type in the following command.
|.357 Magnum, AR2 Pulse Rifle, Crossbow, Crowbar, Gravity Gun, Mega Gravity Gun, Pistol, RPG, SMG, Shotgun, Tau Cannon, .357 Revolver,|
|Portal Gun, Turret, Rocket Turret|
|Scattergun, Pistol, Bat, Rocket Launcher, Shotgun, Shovel, Flamethrower, Backburner. Flare Gun, Fire Axe, Axtinguisher, Grenade Launcher, Stickybomb Launcher, Bottle, Minigun, Natascha, Sandvich, Fists, K.G.B, Wrench, Syringe Gun, Blutsauger, Medigun, Kritzkrieg, Bonesaw, Übersaw, Sniper Rifle, Submachine Gun, Kukri, Revolver, Electro Sapper, Knife|