4 or 9
The queen bee's abdomen is longer than the worker bees surrounding her and also longer than a male bee's. Even so, in a hive of 60,000 to 80,000 honey bees, it is often difficult for beekeepers to find the queen with any speed; for this reason, many queens in non-feral colonies are marked with a light daub of paint on their thorax.The paint usually does not harm the queen and makes her easier to find when necessary.
Although the color is sometimes randomly chosen, professional queen breeders use a color that identifies the year a queen hatched, which helps them to decide whether their queens are too old to maintain a strong hive and need to be replaced. The mnemonic taught to assist beekeepers in remembering the colour order is Will You Raise Good Bees (white, yellow, red, green, blue).