the colour of the sky in a pic is correspond of the colour tempture, which varies with the time of a day, the thickness of the cloud, ...
your picture was taken at 8:42 am, the other one taken at 11:09 am, your picture taken as jpeg format with a fixed white balance, his taken with RAW format with which the colour tempture can be adjusted, and .........................
the colour of the sky in a pic does not depend on the exposure, but make sure of getting the correct exposure with the sky.
the polorizer does not help to change the colour of the sky when you use a digital camera, but you can use the filters in the post-process or in PS.