To keep their raw industrial look consider coating them with clear Rust Guard / wax or Penetrol type product available at the hardware.
Alternatively you can use a coloured spray paint, again I suggest a spray paint that is rust preventing and contains a primer. You may need to clean the legs when you get them using a rag or better still, steel wool.
Black / White Powdercoated):
These legs are primed and powdercoated against rust, suitable for indoor and outdoor use.
Clean with soapy water as required.
Pricing Includes Postage
Made to suit 25cm dia pots.
For use indoors and outdoors. Sturdy 10mm thick steel.
Made in Australia.
Pot not included.
CURRENT LEADTIME 1-2 WEEKS