Sunlight shifts reddish as the sun sets and its blue light is Raleigh-scattered away by a thicker slice of atmosphere. This also makes it dim enough to look at

Sunlight shifts reddish as the sun sets and its blue light is Raleigh-scattered away by a thicker slice of atmosphere. This also makes it dim enough to look at directly. At its zenith, when the sun is whitest, it can't be naked eye observed, so the balance of subjective impressions is formed by late-day observations when its color is shifted toward yellow/orange/red.