in this specific case, they are colors in three different Vallejo paint lines
the first is Model Color
the second is Model Air
and the third is Vallejo's PolyUrethane Primer series
(there is a fourth possible place for the same color, that is in the Panzer Aces series, those are existing Model Color paints given a number as a Panzer Ace color)
otherwise, in a more general sense, Vallejo paints can get listed according to what FS number they are closest too, in some charts, you will find FS 34079 on three paints, and one is right one, one is slightly lighter and one is slightly darker,,,,,but, they don't fit close to any other FS, so that is the one they are grouped with
Rex