From Longman Dictionary of Contemporary Englishsky-blueˌsky-ˈblue adjective CCbright blue, like the colour of the sky when there are no clouds —sky blue noun [uncountable]
Examples from the Corpus
sky-blue• No twinkling sky-blue eyes to match a sky-blue uniform.• Inside their front door the walls are covered with sky-blue fur then, further on, with reflecting silver paper.• He's wearing a knife-creased, sky-blue seersucker, safari-style suit.• A dripping sky-blue shutter or the red flowers of a flame-of-the-forest tree were images exploding on the vision after blindness.• The sky-blue teapot held everything together. 