Chaiten Volcano in Chile is still erupting ash and steam over land and sea. The image from NASA below shows a blue-green plume along the coastline which is likely to be ash and pumice in the water. The inland lakes to the east show a similar blue-green colour which could also be from volcanic material. A fresh ash delta extends into the harbour and mud has also filled the river channel forcing a slurry of ash and water over the banks of Rio Blanco and through the town's streets. The volcanic plume appears to be hugging the valley floors as it moves inland, leaving the mountain peaks clear.
This image, also from NASA is a false-colour thermal radiation image of the volcano at night.
The light colours are high temperatures (the caldera). The dark colours are lower temperatures (the ash plume)