RealFlow | Cinema 4D's simulation and scene elements provide several display options:

With "Visible in Editor" and "Visible in Renderer" it is possible to show and hide a scene element. The mode of operation is exactly the as with standard Cinema 4D objects.
"Use Color" and "Display Color" effect daemons only.
By default, the RealFlow | Cinema 4D logo is visible once there is a "Scene" object. To hide it go to Scene > Display > Display Icon.
Some daemons can be bounded to a certain volume. This bounding volume is displayed in the viewport; handles allow you to change the volume's size interactively.

Fluid containers provide a wide variety of options to customize the particles' look under Fluid > Display.
For detailed information about how to work with the "Display" settings, please open → "Fluids : Display".
If you have attached → render objects to a fluid container you can decide whether you want to show the objects in the viewport or at render time only: Fluid > Particles > Child Objects > Render only.

Only objects with a → "Collider" tag are able to interact with RealFlow | Cinema 4D particles.

In order to improve → fluid-object interaction you can visualize an object's collision geometry with Collider tag > Display > Show Collision Geometry.
This option draws a red mesh around the object; the mesh reacts on your settings made under the tag's "Property" tab.
Under "Display" you also see "Display Collision Velocity". This option is available for animated objects and displays its velocity as red lines: the lines' length is an indicator for the object's velocity.
Reset the scene or scrub the timeline if the mesh/velocity is not visible.

Meshes provide vertex maps for the vertices' individual X, Y, and Z velocity components.
If you want to use the combined speed values instead go to Mesher > Channels > Speed.
The individual "Scale" values are used to enhance the difference between the velocity values: with smaller values, e.g. 0.2 you normally get better results.
By default, the velocity distribution is only visible at → render time in conjunction with a material.
When the mesh is made editable it is possible to preview the colour range (see right image below) by clicking on a vertex map. Of course this action will make the mesh an object and you will lose all parameters.

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