Brown coolant???

I have just got the elbow coolant tubes and a whole new tensioner pulley assembly replaced due to leaks there. Well, my "low coolant" light still pops on and off. I checked the coolant yesterday and it was all brown-ish. What does this mean?

Nevermind guys. Just realized it's the extended life coolant. I read somewhere about a coolant that comes w/ this vehicle being not good for it. Is this the kind?