The name "silverballi" seems to be used to designate a really large range of species in the genus Ocotea of the family Lauraceae, the laurel family. So large in fact that it is broken into groups of species, called the "hard" and "soft" groups. I have no specifics on the breakdown by species, but the range of characteristics within the entire set seems to be fairly extreme, since the "hard" group is moderately dense to very dense (40 to 60 lbs/cubic foot) and used for ship decking and at least some of the species in the "soft" group are so light (25 to 35 lbs/cubic foot) that they are used for canoes and rafts). SO ... basically, the name "silverballi" seems to be about as specific as the term "wood".
As nearly as I can tell, "brown silverballi" is a whole 'nother wood and has its OWN set of confusions since it is a name used for at least three apparently unrelated species (Licaria Canella, Cordia alliodora, and Nectandra globosa) and to further add to the confusion, some of the "brown silverballi" species share other common names with the other silverballi speces. For example, the name kereti spans both sets.
Similarly, "yellow silverballi" is still another set of woods, all in the genus Aniba (specifically, at least Aniba hypoglauca and Aniba Ovalifolia)
I do not contend that the following list is complete, but it was all I could find
both sides of a sample plank of white silverballi / Ocotea canaliculata --- HUGE enlargements are present. This sample was loaned to me by David Clark whom I thank for this and other contributions to the site. This piece is VERY light, to the point of almost feeling like balsa.
end grain and end grain closeup of the piece directly above