Blue-gray and Cerulean

Blue-gray adjective - Of grey tinged with blue.

Cerulean and blue-gray are semantically related in sky topic. In some cases you can use "Cerulean" instead an adjective phrase "Blue-gray".

Cerulean adjective - Deep blue like the color of a clear October sky.

Blue-gray and cerulean are semantically related in sky topic. You can use "Blue-gray" instead an adjective "Cerulean".