Gold filled: These pieces will not tarnish under normal circumstances, including long-term every day wear and water exposure. There have been, however, instances of gold filled jewelry tarnishing when exposed to Sulphur dioxide, but this is an extremely rare and specific circumstance.
Please note that if you have a piece that contains components of gold-filled and gold-plated/gold-vermeil, you should not expose this piece to water, sweat, perfumes, etc. Treat this piece with the care that the lesser quality component requires.
Gold Vermeil: As the base of gold-vermeil jewelry is silver, it is possible that vermeil jewelry will tarnish over time and as some of the gold layering wears away. However, as with silver jewelry, the tarnish can easily be removed.