Facility
Worker spawner
Used for creating new workers of your color and upgrading them.
The upgrades of this facility specifies the properties of workers at a certain level. For example the workers of level 3 benefits from the facility's upgrades at level 2 and 3, and the workers of level 5 benefits from the facility's upgrade at level 2, 3, 4 and 5.
When you produce a worker you have to wait some time before you can produce antoher one or spend crystals to produce more workers on the same recharge cycle.
The level of newly created workers are in the range of 1 to the level of this facility. Most likely the lower lewels.
Worker modulator
The Worker modulator gives you the ability to modulate the color of your workers. This enables you to harvest crystals other then the ones of your color. You can only modulate workers to their neighbor colors, e.g. if your color is Gelbur, you have to modulate a worker to Hadranium before you are able to modulate him to Azon.
You'll have to upgrade the Worker modulator to increase the number of supported workers for the different colors (your own color is not limited by default). The numbers of supported workers for the different colors are shown on the upgrade tab.