If I take the wings of the morning and dwell in the uttermost parts of the sea, even there thy hand shall lead me, and thy right hand shall hold me. In life there is about as much darkness as there is light. As in nature, darkness and light are fairly equally divided. Our idealized image of life is that it is problem-free, with no dark spots at all. But that is a myth, a universal myth, but a myth no less.
Colors have symbolic meanings in all cultures.
For the Romans, white was the symbol of happiness and black of misfortune. In a trial a vote for acquittal was cast with a white stone, for condemnation, a black one. A happy day was marked with a white stone, and an unhappy day with a black stone. According to Pliny the younger, many Romans kept an urn at the door. At the end of a day the Roman would judge his day to have been good or bad.