Both are Bronze and White Bronze are strong, resist corrosion and breakdown, are solderable, non-magnetic, smooth and virtually non-porous.
White Bronze is a perfect alternative to nickel and silver. It has the look of aged silver, but the advantage is it does not tarnish. Your pieces will not turn black. Though, I have heard that over time they can take on a warmer look.
There are two reasons for the recent appearance of white bronze in the rosary making and jewelry world. Many people have developed nickel allergies. A documented 15% of the US population...as opposed to 10% during the 80's. With allergies to nickel on the rise, it is no wonder that nickel is being banned for jewellery use in the European Union.