The alchemical symbols of the four elements: earth, water, air, fire.
The underlying assumptions of many magic systems stem from the ancient philosophy of the four elements: Air, Water, Earth, and Fire. Sometimes, you find those stark elemental hues blended into half-tones (Mist, Mud, Magma, and Smoke), or even smeared into chromatic gradients of varying magnitude like colors on a wheel. That array of elements can be imagined as occupying a single plane defined by the X and Y axes, if you are into the geometry of things. A relatively recent addition to this arrangement is a Z axis, where authors and creators have place the dark and the light hues of Life and Death, or positive and negative energy, or whatever other labels have been slapped onto the concepts, like so many port-of-call stickers on an old-fashioned steamer trunk.
Applying that to my setting:
The Enfae dreams are parallel realms arrayed along that Z axis. The Enfae's native realm is closer to the white-anima realm of life-force than the principle realm of the setting. Because of that proximity, the Enfae (and most fae beings) have strong affinity to the forces of life, while at the same time, their ability to transit through realms along the Z axis also reveal a potent affinity. Their ability to transcend realms in that axis strongly polarized the fae, making the ability to manipulate or control the more conventional elemental energies difficult if not impossible. While the Titan and their minions had strong elemental mastery in that aforementioned XY plane, but lacked any affinity on that Z axis.
So what does all that mean?
Not a goddamn thing... just another way of looking at things, or more to the point, how I tend to look at them.