I also agree with Andy - changes in the light at different times of day produce changes in the colour temperature. Most times the auto white balance setting will do a goodd job of getting it pretty much bang on. Sometimes however when there aren't a range of colours & tones in the image it can be fooled a bit.
The easiest way to correct this in Photoshop is to add a curves layer and then with the middle one of the three eyedroppers below the grid, click on an area of the image that you want to be a neutral shade of grey. In this case, assuming the the superstructure is true white (it may not be of course) clicking on the front indicates that in your image, as well as removing a little blue, it needs a tab of red and a smidge of green adding.
Hope this helps
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