actually i think theres a dust particles on/off button in the options menu. have a look.

The Fleet Admiral thinks were insane ,
Thats just the name of our game .
The Squadron Leader just kicks our @$$ ,
Were gonna need a hall pass .
1, 2, 3, 4, Right, Left, Right, Left.
1, 2, 3, 4, Right, Left, Right, Left!

Space dust is actually just a component of the system that you're currently in, not some global thing that applies to all systems. Consider data/universe/systems/li01/li01.ini, which contains the following:

[SystemInfo
name = Li01
space_color = 0, 0, 0
local_faction = li_p_grp

[Archetype
....
[EncounterParameters
....
[TexturePanels
....
[Dust <----------------
spacedust = Dust <-------------

[Music
....

By removing the indicated lines, no more space dust will appear in Li01 (the NY system).

Additionally, you might want to remove the contrails from the ships, since these also give an indication of motion; to accomplish this, open data/equipment/select_equip.ini and find:

[AttachedFX
nickname = contrail01
particles = li_contrail <---------------
use_throttle = true <---------------

Removing the selected lines (particularly the first one) will make the contrail effect not produce any visible results, thus making it appear that there are no contrails.

Anyway, hope this helps with whatever you're doing.

I've seen the options setting, but I think it just turns off some larger particles, not the basic ones. Will see about the ini file, though. Thanks.

I think he means the small white dots, that look like StarTrek Warpspeed somehow.

I would suppose there is only one type (=small whited dot) and it's hardcoded. The space dust in some nebula/asteroid fields can be turned off in the settings ("background dust".