light and darkness; light and shade
Refers to the contrast between light and dark, both literally and figuratively (e.g., fortune and misfortune, clarity and obscurity).
The contrast between light and dark in this photo is beautiful.
I have experienced the ups and downs of life.
This one game decided which team would come out on top and which would fall behind.
Adding light and shade to the photo gives it a sense of depth.
There was a stark difference in fortune between the two athletes.