Hoover and Strong sells a ‘bright white’ alloy that is supposedly
whiter than a nickel or Pd based gold colour. I didn’t notice much
difference in their 18 kt de-ox white and the “new” alloy myself when
a student bought some to cast some pendants in a relatively small
run. On the whole however, their colours seem a bit better than most
in 14 karat golds.
With 18 karat there is less room for additives in basic karating. the
other consideration is that if you are to solder most vendors sell
Hoover and Strong manufactured solders in the widest range of colours
so finding a matching colour would be easier if you use their grain
or master alloys, if not their mill products. rer