yup. that's the bad thing. the pictures were either before it was about to rain or after raining. however, i don't think that it ruins the photo because the colours couldn't get much better even if it was sunny..
for colours.. might be the limitation of a camera phone.. but in any case.. you can consider tweaking curves (or up the contrast) during pp..
as for composition.. you might want to consider the few "golden guidelines".. what is the subject.. does the picture lead the eyes (via some pattern / leading lines) to the subject.. are there extraneous elements in the frame that distracts.. are the horizons and the buildings tilted.. if they are then do they make dramatic sense or tension to remain tilted.. etc etc etc..