primary colour
noun [ C ] UK (US primary color) uk/ˌpraɪ.mə.ri ˈkʌl.ər/ us/ˌpraɪ.mɚ.i ˈkʌl.ɚ/
原色，基色（指能混合成其他各种颜色的红、黄、蓝三色之一）
one of the three colours, red, yellow, and blue, that can be mixed together in different ways to make any other colour
Compare: secondary colour