I know nothing about tiling but I do know about cameras - a lot of interior pics I've seen of jobs have a nasty orange colour from the artificial lighting. Use a decent camera that has adjustable white balance (usually has settings for sunny, cloudy, or artificial light, plus sometimes a few other settings) and hey presto those bumpy whites will look white :smilewinkgrin:
A lot of people get hung up on megapixels but that's essentially meaningless these days - what matters is the quality and size of the lens, and mobile phones have tiny ones. You could have a 20mp camera with a cheap lens and it would still take useless pics, whereas I had an old 2mp Olympus camera circa 2002 that took great photos (got enlargements on my walls!).
After all, the megapixel count only measures the sensor, which is equivalent to the film in an old camera. You could put top-notch slide film in a plastic point-and-shoot and it wouldn't take any better photos than with a freebie roll of film from Snappy Snaps...