Pastel, being the lightest series of the grey line (having 2 blue genes) color, especially at hatch, can vary, depending how the parents were created.
Mating 2 blue fawns can result in a pastel (25% chance).
Mating a blue fawn to a pastel has half a chance of producing more blue fawn, and half pastel.
Only way to be sure of pastel, is mating pastel to pastel. But if one had a blue fawn parent in recent generations, it can determine how dark the pastel color ends up. Kinda like splash chickens. Some show much more blue than others.
Dusky could be involved, but I can’t tell. I would hope an eBay seller would indicate if the dusky gene could be involved. I bet they have longer lines of pastel, making them really light. Just a guess.