A balanced view
The dominant light source in many city scenes is often tungsten and sodium street lighting, both of which produce a very warm, yellow colour cast. You can set automatic white balance to neutralise this, but this tends to result in images which are too cold and clinical. The fact is that even to the human eye, cities give off a warm glow, so it’s important to try to preserve this if you want your images to look natural. This is particularly the case with a building like the Houses of Parliament, which is bathed in warm tungsten lighting. If in doubt, shoot in RAW and then experiment with the white balance afterwards.