have a 08 flstf changed the rear tire and while i had it down i changed the brake pads
now looking at the rotor it seems to be blue color
used stock harley brake pads and there is no squeaking noise
is this normal

 

Somewhere on here it was posted you should lightly clean the rotor with 400 grit sand paper when changing the pads.

The blue color may mean that your brakes got a little hot. They should be OK as long as they are not warped. How many miles do you have on your bike? Rear pads usually last longer than front pads. You may be unintentionally dragging the rear brakes. I got 7,000 miles on mi fronts and 10,000 out of my rears.

 

Blue rotors like blue pipes means that at some time in its life it got heated more than is considered good for it.
A 'very' general rule of thumb is that if you can sand/grind off the blueing it 'should' be OK for now. But repeated heating to that level is not a good thing and will eventually lead to warping at best and cracks radiating out from the cooling holes at worst. Personally I wouldn't bother, if your heating them up far enough to turn them blue because you like to ride hard and not because you are resting your foot on the pedal all the time. I think its time you started looking into replacing them with a good set of two piece floating rotors.
Floating rotors can withstand higher brakeing forces better because they cool faster and more efficiently than solids. Their floating nature also allows them to move with or in the pads better to maintain a more even and consistant pad contact for more even heating, and better brakeing.

 

well i have 12000 miles on it and front looks ok guess i use the rear more than the front

 

They should have went over your rotor to remove any glaze build up. I have seen the glaze (if not removed) take on a blue haze color after installing new pads.

 

I'm curious how many miles you have on an '08 to change the rear pads already? I just changed the rear pads on my '07 at a little over 16K, and the front pads are still in good shape.

 

I think a lot of guys instinctively use the rear brakes harder on bikes with the skinny front/fat rear tire configuration ours have. Many may be unconsciously afraid of locking up that skinny front tire. I KNOW I am because I did it once many years ago on my first bike, a drum brake Honda CB175 and I have no wish to repeat the results of that little mistake.
As a consequence of that I have ever since habitually used the rear brake much more/harder than the front and use the front to moderate how much more or less I need to suit the situation.
So it would not surprise me at all to find out that the rear brake pads wear out faster than the fronts. In fact I would expect it on my bike given how I use them.