The only criterion for determining whether an olive is dyed or not is the pith. If it stains your hand when you hold the olive, it means that the olive has been dyed. At the same time, if the pith of the olive you eat stains your hand, it is also a dyed olive.
Here's a tip to help you tell whether olives are dyed or not; if you squeeze an olive between two fingers and it leaves a purple or blue mark, you can tell if it's a dyed olive.
The pits of unpainted olives are brown in color.
We should look at the natural appearance of the olives we buy, not their size. Fermenting olives naturally is a laborious and long process. To speed up this process, some additives are added as catalysts. These methods are not correct at all.
Impure olives may contain the following additives; food coloring, iron rust and chemical additives.
As Mavras, we do not use any of these and only use rock salt to make table olives.