... Use Vertex Maps 2?

This approach uses two materials. First, a “RealFlow Mesh Importer” plugin is required where the sequence can be loaded. The vertex maps are generated automatically when you start scrubbing the timeline. With MD files you have the greatest choice, assuming that you have exported the appropriate channels with your mesh. Weight maps are only available for BIN files.

• Create two materials, e.g. a white and a blue one – you will also find these colours in a particle emitter's “Display” panel in RealFlow. The settings there are responsible for the particle simulation's colours, and we want to achieve a similar look here.
• Attach the materials to the mesh node, but be careful, because the order is important: blue represents the lowest value, white the highest one. So, start with blue, followed by white.

• Open the white material, and activate the “Alpha” channel.
• Texture > Effects > Vertex Map
• Click on the white square.

• Drag one of the plugin node's vertex map tags (e.g. “Age”) to the material's empty “Vertex Map” slot.

It seems as if this process did not have any effect at all, but when you render the scene you will see coloured areas. It is very likely that the result does not meet your expectations, because it lacks contrast. To fix this, proceed as described here:

• Open the plugin's “MD” panel (only available with MD files).

• Look for the channel you have used in the white material, e.g. “Age”

• Increase or decrease the channel's “Scale” parameter to change the ratio between blue and white areas until you get the desired result.