differences in caper berry seeds
forgive me for asking, but are your capers perhaps in a jar with peppercorns? 

if so, this might explain it

sadly i'm not an expert on this plant, but they might be like other flowers (a sweetpea for example comes in several colours)

oh-- i will not post a pic because someone will take points from me, but as you love capers it might interest you to know that they grow on the Western Wall in Jerusalem :)

if your caper habit becomes too expensive you might try Pickling Dandelion Buds &amp; Nasturtium Buds