Most beekeepers place a small dot on the back of their queens to help keep track of their queens age, amongst other things. A felt tip pen is often used to accomplish this task. There are a variety of techniques for getting the queen to sit still for the marking... we will not get into all these, at least not in this post.
The color used to mark the queen is based on the last digit of the year the queen was born. Beekeepers can also mark with a number. These are small disks that are literally glued to the queens back. This allows for more detailed information to be tracked that just a color code. The vast majority of tracked information is typically associated with genetics - whos your daddy??? or in this case, more often than not, whos your mama and what is the history of your colonies honey production!
So if you ever see a honeybee with a paint mark on her back (usually a round dot, but some beekeepers have been known to mark with what could be considered a racing stripe) you know she has, or had, a home in a beekeepers apiary!
Sandy Bee Mine