What do the following words have in common purple orange turquoise month?

The words purple, orange, turquoise, and month all have the following in common:

* They are all nouns. They represent things or concepts.

* They are all common nouns. They refer to general things or concepts, not specific ones.

* They are all related to color or time. Purple, orange, and turquoise are colors, while month is a unit of time.

While the connection between color and time may seem tenuous, they are both abstract concepts that we use to describe the world around us.