Well, don’t underestimate the time-of-day factor: for most humans, nearly everything looks better at 8:00 P.M. than at 5:30 A.M.
However, in this case you’re righton most days, sunsets are much more brilliantly colored than sunrises. It doesn’t make sense, since most of the same conditions are in place for eacha sun in a low sky sending rays careening through Earth’s atmosphere. So what gives?
Credit humanity. Or rather, blame us. During the day we generate the bulk of our traffic exhaust and factory smoke, which lingers long enough to give brilliance to our sunsets.
During the night, much of the pollution gets blown away from population centers, so less of the blue light gets scattered, resulting in less intense reds and yellows in sunrises than in sunsets.
