YOU SAID:

red blue yellow are the primary colours

INTO JAPANESE

赤青黄が原色です

BACK INTO ENGLISH

Red, blue and yellow are the primary colors

INTO JAPANESE

赤、青、黄色が原色です

BACK INTO ENGLISH

Red, blue and yellow are primary colors

INTO JAPANESE

赤、青、黄色は原色です

BACK INTO ENGLISH

Red, blue and yellow are primary colors