Mana can exist in many different states, called aspects. The kinds of effects mana will have on the world is dependent on what kind of aspect it is currently colored as.
As soon as pure mana is absorbed from the environment into someone's core, it takes on that person's natural aspect. For humans, that could be any primary aspect. When mana is channeled into a spell, it must be done so as a particular aspect. Spells are categorized by the aspect required to cast them.
There are nine primary aspects, each of which has a natural counter-aspect, except for hex, which counters itself. Spells of a particular aspect are especially strong against people who have cores
of the counter aspect. Each primary aspect also has a distinct color, which is mainly just a symbolism thing for writing, but also is a real thing; physical manifestations of mana usually glow with their associated color.
Different aspects can be mixed together to form compound aspects. Compound aspects typically have much narrower uses compared to primary aspects, but they can allow for powerful spells. They also have the benefit of being counter to two primary aspects; for example, a lightning spell is effective against both people who have water cores, and people who have earth cores. Also, color associations go out the window with these, it's just whatever I feel looks appropriate.
The following compound spell classifications are not aspects of their own, but are comprised of three or more, sometimes counter, aspects. They are incredibly niche realms of magic, and usually only pursued by experimenters and researchers.
Advanced golemancy (necrotic+earth+hex+holy)
Dimensional magic (shadow+air+holy+light)