You might have noticed the coloured ring around the levels of your resource fields or buildings. Below you find an description of their meaning:

Blue:
This building or resource field at its highest possible level.

Green:
You have enough resources of all types available and at least one free slot left in the building queue.

Yellow:

• Your building queue is filled but you have at least one free slot available in the master builder queue.
• You have at least one free slot left in the building queue and enough resources if NPC is used.
• You do not have enough resources but at least 1 slot available in the master builder queue.
• You have no free slot left in the master builder queue and enough resources if NPC is used.
• You have enough resources available but no free slot in the building queue and master builder queue.

Grey:
Everything else.