This paper presents the concept of a service colony and its characteristics. A service colony is a novel architectural style for developing a software system as a group of autonomous software services co-operating to fulfill the objectives of the system. Each inhabitant service in the colony implements a specific system functionality, collaborates with the other services, and makes proactive decisions that impact its performance and interaction patterns with other inhabitants. By increasing the level of self-awareness and autonomy available to individual system components, the resulting system is increasingly more decentralized, distributed, flexible, adaptable, distributed, modular, robust, and fault-tolerant.