Hi,
Without seeing it in my hand for details and fabrics, etc, I say it is late 1950's..circa 1957 to 1960. In 1957 the turban was re-introduced in women's millinery, and by 1958 was again popular, although stylized for more "moderne" tastes. The Paramount film "The Loves of Omar Khayyam" (1957) influenced fashion and hats, and many hat makers brought out a line of turbans in 1957 to follow suit. The one you show, I think, may be backwards or sideways in the photo? It appears slightly smaller in scale, and the satin looks a bit heavy (?) and so may be leaning to 1959 to 1960.
I am a fan of Coralie hats, and the colors on this are wonderful.
Regards, Barbara