What blue Glocks are we talking about? The only blue Glocks I know of are the inert trainers that don't fire live ammo, like this one:
Now, if you're talking about the original Glocks with black frames, then astig007 is correct in saying that the color of the frame does not affect the performance of the gun.
The Glock Mariner, OTOH, is different from the regular Glocks primarily due to the maritime spring cups in the firing pin channel that allow said model to be fired underwater. Check out this section of the Glock FAQ for more details.
buy ka na lang ng glock na marui, mga 4,500-5,000 PhP, you could use it to dry-fire at home or even do some movement drills with it... probably even setup COFs' inside the home specially it's rainy season again