I don't like the white cards on the light grey lists. I would like a way to make them stand out more. The lables just put a small strip of color. Can I change the color of the cards, the lists or even the text?
Unfortunately not, coloured backgrounds are currently under consideration as a new feature on the Trello development board, go to Trello dev board and place you vote.
'Card Colors for Trello' is a Chrome extension which colours a card when you add a label and works well. (Would also like to be able to change the colours of list backgrounds, or make transparent...).