BeansProshop may be expert on this subject.
They are all sorts of different balls from the Columbia type companies.
Columbia, Track AMF as stated above.
I just picked up a Hyde and a Wired bonanza, color blems, absolutely beautiful.
That is only flaw and they look better than the suppossed to be color.
I also have a Sonic X which is a blem which looks better than the usual.
All sorts of balls are available like this, from Heavy oil to plastic, with flaws being color pin out too great pin in too small, top weight, out of line mass bias.
But if it is just color, giddyup!
rEgards,
Luckylefty