I love when information is designed so that even the background color denotes a valuable variable, but sometimes it is executed poorly. Take this set of clocks from Mac OS Yosemite. The idea is that white-background clocks represent daylight and black-background clocks represent night time. But I’m not in Sydney so when I look at that clock, I have to pause and figure out if it is 7am or 7pm. There could be daylight at either time. Especially in extreme northern and southern locations daylight can last 18 hours parts of the year.