I've recently come back from a trip to Madrid. The buildings there are a mix and styles and influences, reflecting different cultures and rulers - Moorish, Austrian, French, Spanish - mixing over the centuries.
The weather was not kind to me in Madrid, with cloudy, milky, grey-white skies almost throughout my stay.
I decided, then, to splash in some colour from the city's flowers (many of which were growing in the botanic garden) which contrast nicely with the pale, ice-cream colours of the ornate architecture.
Incidentally, I did something similar with these photos of Rome, taking out the sky and putting in the colours of the Italian flag.