I have read the book that inspired Magic the gathering. It is called "Authentic Thaumaturgy". Some sort of magic RPG system based on esoteric magic.
By checking back at the colors and elements, I used for my game a 5 element system a la magic but white was replaced for yellow. So it made:
Yellow = Science: TIme travel, teleportation, golems, machinery, alchemy
Red= Chaos: Impossible mixture of stuff: Living walls, Chimeras, stone skin,
Blue = Ether: Control of magic it self, magical creatures "dragons, fairies, elementals,"
Black = Spirit: Ghost, mental attacks and effect.
Green = Nature: Weather, dire animals,
NOt even in MTg, there is some ambiguity following this system. For example, they place fire elemental in "Chaos" because it's red but in reality, it should be placed in Ether.
There are other 5 element system. Chinese and japanese use a 5 element system:
Ciinese: Wood, Metal, Water, air, fire
Japanese: Earth, void, water, air, fire
The relation in a 5 point element is as this.
Draw a pentagram between your elements and draw a ccircle to chain your elements. Each elements is good against another elements, THis 5 point Rock-paper scisor follows the lines of the pentagram. Each elements support another elements, this follows the circle around your pentagram.
I made a picture of it as my windows background, I might try to link it Later.