You are confusing two "dark" issues. Dark matter and dark energy.
In physical cosmology and astronomy, dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe.1 Dark energy is the most accepted hypothesis to explain observations since the 1990s that indicate that the universe is expanding at an accelerating rate.
Your question is appropriate for dark energy, which permeates everything, and the dark is taken to match the terminology for dark matter, which was a phenomenon observed much earlier.
Dark matter is a type of matter in astronomy and cosmology hypothesized to account for effects that appear to be the result of mass where such mass cannot be seen. Dark matter cannot be seen directly with telescopes; evidently it neither emits nor absorbs light or other electromagnetic radiation at any significant level. It is otherwise hypothesized to simply be matter that is not reactant to light. Instead, the existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total content of the universe.
Dark matter has been hypothesized to explain discrepancies in orbits in galaxies, which can be observed/measured and the solutions of the equations that would describe them, given the mass measured from the luminosity of the systems. The orbits said that more mass was in the system than the one emitting the light we observe and measure.
Thus the all permeating vacuum dust cannot explain dark matter, it has to be matter attached to gravitational systems.
It cannot explain dark energy either because it is very small, as rob's answer says.