flow visualization

What colors are used for flow visualization in water?

Ordinary dye in water seems to dilute very quickly. I have heard of a dye with alcohol and milk, but I was not able to find information on the relationship between the two components works best.

Try an oil-based dyes – You need something that will not dissolve in water. Polystyrene plates does so if you have only the surface effects are involved.

Flow Visualization part 1