'Appearance' in the Bible

“Whenever you fast, do not put on a gloomy face as the hypocrites do, for they neglect their appearance so that they will be noticed by men when they are fasting. Truly I say to you, they have their reward in full.

And in the morning, ‘There will be a storm today, for the sky is red and threatening.’ Do you know how to discern the appearance of the sky, but cannot discern the signs of the times?

And his appearance was like lightning, and his clothing as white as snow.