Definition & Meaning of "(as|) brown as a berry"

What is the origin of the idiom "brown as a berry" and when to use it?

The phrase "brown as a berry" is believed to have originated in England in the 17th century, when having a tan or darker complexion was associated with spending time outdoors and engaging in physical labor. Berries that are ripe and ready to eat are typically brown in color, and the comparison to a brown berry may have been a way to describe someone whose skin was browned or darkened by exposure to the sun. The phrase became more widely used in the 19th century, particularly in the context of describing individuals who had spent time in tropical regions or who had otherwise acquired a deep tan. Today, the phrase is still commonly used to describe someone who has a dark or sun-kissed complexion.