The names of the islands of the Netherlands are Texel, Vlieland,
Terschelling, Ameland, Schiermonnikoog, Rottermeroog,
Rottermerplaat. Those islands don't have capitals. But if you mean
the Netherlands Attilles, which no longer exists (since 2010!):
Aruba with the capital "Oranjestad", Bonaire with the capital
"Kralendijk", Curaçao with the capital "Willemstad", Saba with the
capital "The Bottom", Sint Eustatius with the capital "Oranjestad"
and Sint Maarten with the capital "Philipsburg".