Like any aesthetic judgement its subjective. But there are some real
things that happen. Like Daniel says the contrast of yellow metal
next to top white diamonds makes them pop. On the other hand
sometimes what you’re going after is for the stone section to
represent a generalized shape of whiteness. In the case presented you
have an uninterrupted run of square diamonds with a yellow border(if
I understood the description). Here a white channel flanked by yellow
creates a solid ‘mass’ of white, the illusion is that of a white
stripe in a yellow field. It could also be done with a yellow channel
but the white makes it stand out a bit more. A white channel will
make the princesses appear wider. A quick glance and they may appear
very similar. But buyers tend to look long at things they contemplate
buying. If you can keep their interest you increase the chances of a
sale. Even though they many times cannot articulate the difference
they will still notice them.
A lot has to do with the stone size, shape and layout. Larger stones
can be more sensitive to refraction thru the girdle simply because
they are larger and its easier to see the tiny yellow bits here and
there. I don’t think this should be an overriding consideration
though. The overall design of the piece should remain paramount. If
it becomes a sticking point there are things you can do.
Round stones in a yellow channel, to my eye anyway, is lame unless
they are very small, like.02 and under. Anything larger and you
easily see ‘triangles’ of yellow between the stones. Some people like
the look, but it can appear toothy. If rounds are set in individual
yellow bezels then the contrast thing works well. This is where you
want to see each stone as a separate entity with the metal(be it
bezel or prongs or whatever) being a separate design element that
coordinates with the stone layout.
How much weight should be given to any of this? Depends on the
customer and the maker. What the client likes is what you do if you
want to actually sell it. What the maker is capable of definitely
affects how it should be approached. Ex. a mediocre pave’ setter
might get away with white gold because of what I mentioned before,
the larger white area obscures detail to a degree. The craftsmanship
of the bead work is not as evident as when its done in yellow gold.
But then it comes back to the client…is your client appreciative of
the differences?