Magic (煌術 Kōjutsu) in Skies of Arcadia is organized into six categories, one for each of the 6 known Moons. They range from offensive, status changing, life restoration and healing.
The lowest level spells start off small, but grow more varied and as the color of magic is mastered more completely, upgraded versions become available to the characters. For example, the basic spell of the red magic category, red being the fire element, is a sort of air-burst explosion, with it's full power component being a blast poorly described with the word "explosion." Much like other RPG's the names of the stronger spells are based upon the weaker ones, and progress upwards.
Each class of magic has 2 major chains of spells (with the exception of silver.) The primary chain has four progressively stronger components all of which directly focus on their targets and their comrades, the secondary line of spells attempt generate status effects usually without actually damaging their targets.
When a magic spell is executed successfully, the target(s) are summoned forcibly onto the magic crest of the old world civilization corespondent to the color of magic cast, subjected to the effect of the spell, then returned to wherever they were beforehand. These crests seem to have once been of superior cultural importance, but are only mentioned directly once during the story, when the one of the touchstones in Glacia ask about the "Purple crest" which "hides a number," the answer being two, which is the number of circles at the edge of the purple magic seal. The number of dots around the edge of the seals seem to correspond to the moons, although why which moon is which number is completely unknown. The number of the seals is also strongly reflected in the architecture and symbols of many of the locations related to the crystals. (As a few examples, Recumen has 4 heads, the red crystal has 4 points, Yeligar has 5 major appendages, Zelos has 6 arms, the entire Soltice offensive grid is hexagonally (six side) based; the list is extensive.) The seals are in this order, from lowest to highest: Seal of one; Life (green), Seal of two; Will (purple), Seal of three; Agility (blue), Seal of four; Power (red), Seal of five; Energy (yellow), Seal of six; Void (silver). Oddly the progression of the story has no relation to this order at all.
Eventually players will gain the ability to use magic in battle. However, to cast any spells during a ship battle, you must obtain the item "magic cannon" from defeating Belleza in the battle with the Lynx.
One of the discoveries that appears in the Dark Rift is the Black Moon stone. This however, is simply a curiosity and a novelty. Although the description mentions the possibility of a black moon, no black moonstones are obtainable. There are, therefore, no black spells available which means that there is no active "Black magic" at any point in gameplay.