This paper introduces a Coloured Petri Nets formalism -TCPN- which is suitable for modelling and simulation of complex systems. Novel in TCPN is (i) a timing model which accommodates both unordered and ordered (queue) places; (ii) the adoption of Java as the net inscription language. TCPN is supported by a graphical tool - RAINBOW - which allows model design, testing and simulation. A large TCPN model can be split into regions (subnets) whose execution is assigned to different LP/processors of a networked simulator. Distributed simulation relies on TUTW, an agent-based Time Warp algorithm capable of exploiting temporal uncertainty for improving simulation performance. The paper describes TCPN and its distributed execution kernel. The practical use of TCPN is demonstrated through an example and some experimental results.