Cerulean

Cerulean is an adjective that means sky blue. 

Our word of the day dates back to the mid 17th century and the Latin word caelum (KY loom) which means ‘sky.’ Here’s an example of cerulean in use:

Andrea’s striking cerulean eyes were the first thing I noticed when I regained consciousness in the hospital. The second thing I noticed is the way her blue eyes matched her dress.