There was very little difference in dress between legitimate sailors and pirates. I think by convention people tend to paint pirate-sailors a bit gaudier, and naval-sailors a bit more uniform, but historically there was little difference.
Many accounts I've read said the Dutch preferred yellow coats for their officers. I have no idea how accurate that is, but it seems to be a good and plausible color for them. I also agree on the value of including a priest of any variety, painted in sober, Calvinist black.
The Dutch were pretty much on the wane as a Caribbean power during the Golden Age of piracy, clinging to a few settlements near Eleuthra.