cerulean
adjective
[ sɪˈruːlɪən ]
• deep blue in colour like a clear sky.
• "images of cerulean waters and golden sands"
cerulean
noun
• a deep sky-blue colour.
• "the background was painted in cerulean blue"
Origin:
mid 17th century: from Latin caeruleus ‘sky blue’, from caelum ‘sky’.