How do you protect and finish teak wood patio furniture?

Question

to retain its mahgony color. (no turning gray/silver)

Answer 1

Rub linseed oil on it.  You take a spray bottle of water and spray the wood surface.  If it beads up, then it does not need any oil, if it starts soaking in, apply oil liberally.  Make sure you apply several coats and allow time for the oil to soak in.  Test different areas of the furniture since they get different exposure to the sun.