Corrosion resistant metal for swimwear buckles

A customer is starting a line of high end swimwear featuring large
metal buckles for which I will potentially be creating prototypes.

He’d like the finished parts to have a gold tone finish and be
chlorine and salt water resistant. Cost is a consideration, so real
gold plating is probably out of the question, not to mention, not
very practical in terms of durability over time.

I’m hoping to get some suggestions as to the process to manufacture
the buckles, whether it be to cast in brass or a base metal and
plate with a corrosion-resistant yellow metal, or to cast directly in
some sort of yellow metal that won’t deteriorate with exposure to
salt or chlorinated water.

Thanks,

Jesse
JDK Jewelry Design
CAD/CAM Technology
Handcrafted Originality
http://jdkjewelry3d.ganoksin.com/blogs/