The 4 colors that make up the Frenopolis board are called "elements":
Fire, Air, Water, and Earth

All the board zones and card types are assigned 1 of these 4 elements.

Each card color (Red, Orange, Yellow, Blue, Purple, Violet) are defined as 2-combinations of the elements which comprise the board and the card types.

Defining all effects in terms of these elemental relationships allows a strict correspondence between the game board and color pie. The effect scope of each color is strictly defined and predictable.

You don't need to know this to play – you can just follow the written card text, but knowledge of the underlying design allows for more advantageous play.

The 4 colors that make up the Frenopolis board are called "elements":
Fire, Air, Water, and Earth

All the board zones and card types are assigned 1 of these 4 elements.

Each card color (Red, Orange, Yellow, Blue, Purple, Violet) are defined as 2-combinations of the elements which comprise the board and the card types.

Defining all effects in terms of these elemental relationships allows a strict correspondence between the game board and color pie. The effect scope of each color is strictly defined and predictable.

You don't need to know this to play – you can just follow the written card text, but knowledge of the underlying design allows for more advantageous play.