1. The water in the ponds is clear, yet the ponds present a vast variety of the most delicate shades of colour.
2. There was no swimming either, but I guess it's hard to get excited about water the colour of cappuccino.
3. The " colour " of the ocean is determined by the interaction of light with the water.
4. So much effort has been made and so many years have passed but the water is still yellowish in colour.