The JackBord Light Stick contains 10 RGB LEDs.
You can control the color and brightnes of each LED from the JackBord. 
Light sticks can be connected in series or parallel to make more complex displays and can be used for things like sensors to indicate readings. The portable soil moisture meter project is a good example.  
Having multiple Light Sticks provides more flexibility to make more complex light shows or displays. They could also be used as a light source for growing plants and experimenting with different light colours and plant growth.