This ink is the reason I wanted my first real fountain pen about a year ago. The color is a dusty purple, something you would maybe see in a gorgeous painted sky as the sun sets. Yeah, that sounds cheesy, but this color really is that great.
Poussiere de Lune is an almost pastel purple that leans more toward the blue side of the spectrum than the red. Think diluted Grape Kool-Aid, and you’ve pretty much got a spot-on idea of the color. PdL would be related to Private Reserve Ebony Purple and Sailor Jentle Chu-shu, perhaps their younger sibling. It is very unique and obviously from a fountain pen. This color is subdued and I believe you could use it in a professional setting- given you were not restricted to blue or black ink only.
To speak of the technicalities- it is an average to slightly dry and less saturated ink, but it is very nice. There is a decent amount of shading. This Herbin offering could stand to be a little bit more lubricating, but it is pleasant to use. Many people have commented how surprising the water-resistance is, and I have to concur. I have a feeling that as school approaches, I will be using this ink with a nice smooth medium nib to take notes. This is definitely an ink that I will buy again.
Here is a comparison shot with some other purples: