duck-egg blue adjective 1noun 1forms 3 adjective1 •Of a pale greenish blue colour, like that of some duck eggs.The walls were duck's-egg blue and in the centre of each was a colour print of tropical flowers in a bamboo frame. — 1954 noun1 •A pale greenish blue colour, like that of some duck eggs. formsduck-egg blues · more duck-egg blue · most duck-egg blue