Here, "china" means porcelain ceramic plates and dishes, originally from China (the country). But porcelain is not blue; ceramic is not blue. "china blue" is the color of the paint traditionally used to decorate "china". Angela quotes a dictionary entry that describes "china blue" as "a bright greenish blue", but famous china patterns such as the Willow pattern look to me to have a pure blue hue to them with no hint of green. So, that definition doesn't seem right to me. I would describe "china blue eyes" as being of a strikingly pure and almost luminous blue color. See https://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Blue_Willow_china%2C_c._late_1800s%2C_Lahaina_Heritage_Museum.JPG/220px-Blue_Willow_china%2C_c._late_1800s%2C_Lahaina_Heritage_Museum.JPG

Hi Jessica. China is a fine and exceptionally white kind if ceramic (porcelain) made of a mineral called kaolin and developed in China. The sentence is like "ceramic blue eyes" or "porcelain blue eyes". I hope it helps. Rafael.

Hello, China blue is a bright greenish blue. Best, Angela