Microfluidics and fluid colour

First of all, sorry if this is in the wrong section.

I am trying to simulate a rotating body in a blood vessel. As such, the dimensions are in the micrometer range. I already have an animation working and managed to render it to an .mp4 file, but the dimensions are obviously not microfluidic, even though the meshes were drawn with the desired sizes.

That is the first doubt. Can Blender do microfluidics? I’ve tried only changing the scale but I either lose the objects (they go into a mysterious magical vacuum) or the software automatically resizes them back to the metre ranges.

The second doubt, I need to colour the fluid according to it’s velocity. I know that is feasible and easy with a particle system, but the computer I’m using runs out of memory before reaching the needed particle number in order to simulate something to a wind tunnel. Of course that might be solved if the micrometre range is achieved.
If not, how can I colour the fluid that results from the fluid simulation? I’ve tried a colour ramp and a Particle Info node, but it didn’t work.

Something like this?

Oh my god that’s beautiful…

I tried it (working currently on a Mac) but I can’t seem to make it work. Or even install it correctly, OpenVDB keeps on failing.

Is there any other way? I’ve google and googled and by god I can’t find anything decent.