The colours red, green, and blue must each be present and the remaining quark and antiquark must share corresponding colour and anticolour, here chosen to be blue and antiblue (shown as yellow).
The colours red and blue must each be present. This is green. The remaining quark must share corresponding colour and anticolour chosen to be blue and antiblue (shown as yellow). This was here. Antiquark must share corresponding colour and anticolour chosen to be blue and antiblue (shown as yellow). This was here.