N-GREEN is a cost attractive optical ring network which uses coloured packets. It is normally fit to a predictable traffic with a low burst rate, found e.g. in the metro aggregation. Here we try to adapt the network to other, potentially interesting applications where the traffic is more bursty, by proposing a packet management scheme with adaptive expiration times, determined in response to local and/or global queue sizes. The exact relation is found using a direct optimisation method which uses a simulation. We show that thanks to the regulation of the expiration time, an N-GREEN ring may continuously adapt to a bursty/unpredictable traffic of a varying average load, provided the nodes inform one another about the momentary size of data in their input buffers. The adaptation may considerably decrease the latency of the network