According to the teachings of Atlantis and the Ministry of Magic, all magic has two colours, the discipline colour and the signature colour. The discipline colour gives some indication of the magic’s effect, while the signature colour gives some indication of who cast the magic. They do not mix - someone using magic sight can see both colours simultaneously.
The Seven Disciplines
The Atlantean Rainbow Theory divides magic into seven distinct disciplines, most of which come in opposing pairs. The disciplines are destruction and creation, sight and illusion, binding and protection, and change.
Each discipline is assigned a colour from the rainbow - red for destruction, orange for sight, yellow for binding, green for change, blue for protection, indigo for illusion, and violet for creation. Some mages prefer to call the last two colours teal and blue, respectively.
The destruction discipline covers magic that can be construed as destructive. So, that includes obvious things such as fire and explosion, as well as less obvious things such as darkness (destroying the light) or cold (destroying the heat). Magic dispel spells also fall in the destruction discipline, as they essentially destroy an active magical spell. Laser beams and lightning are also classified as destruction magic.
The sight discipline covers any spells that directly grant you information, not just visual information but any information. Scrying spells are the obvious thing here, but there are several other things that can be classified as sight, including magic scanning spells (such as the spell that enables magic sight in the first place, but also more in-depth scanning spells), hearing enhancement, telescopic vision, etc. Spells that take information from a specific source, such as mind-reading, do not fall under the sight discipline.
The binding discipline covers a wide variety of spells that limit, constrain, or enhance. Perhaps the most well-known spell in this discipline is the geas, but there are many other spells that qualify as binding, including curses, general buff or debuff spells, certain types of charms (like a good luck charm), and generally speaking any spell that alters the property of a thing without altering the thing itself.
The change discipline is also quite broad, covering not just physical transformation but also mental magic, soul magic, teleportation, time travel, summoning, and healing. Any spell that changes something on a permanent basis falls into the change discipline.
The protection discipline covers magic that blocks, inhibits, or turns away spells or other influences deemed harmful. This includes physical force barriers as well as mental barriers, anti-scrying protections, or magic dampening fields that interfere with all magic inside them.
The illusion discipline covers magic that creates false impressions that anyone within range can detect. (False impressions detectable by only certain people would be mental magic.) These false impressions can affect any of the six senses, though the method of deceiving magic sense has been largely lost.
The creation discipline covers magic that creates something out of nothing. This does not include transient creations that fade with time - those would fall under illusion or binding, depending on the exact method. Like change magic, creation magic is permanent. A strong mage skilled in creation could easily create enough food to sustain themselves, for example. Light spells are amongst the easiest creation spells, and the creation of electrical current would also fall in this discipline.
Magical Signatures
All magic channelers (which is approximately 80-90% of all magic users) have a unique magical signature that identifies any spell they case. In fact, even non-mages have a weak magical signature in one of these colours, typically silver unless a racial colour supercedes it (eg for djinn or fae). Though it’s possible to erase the magical signature from a spell, few learn the means to do so as it requires channeling a different sort of magic and thus requires a different sort of training to master.
Different types of magic sources show up as different kinds of colours in magic sight. One particular type of magic is unique, in that it gives the impression of colours even to non-visual magic sense - this type is referred to as “The Gift”, or sometimes “inherited magic” since having a parent with the Gift greatly increases a child’s chance of also having it. Every Gifted mage has their own unique colour, which is always a simple, solid, saturated colour. Common colours include red, green, blue, purple, yellow, orange, or pink, but any colour that can be named is possible as long as it’s not some shade of grey.
For most other types of magic, the colour only uniquely identifies the type of magic, rather than the individual caster. Some colours are patterns of multiple colours rather than a single solid colour. The following list is comprehensive for Earth; additional varieties can occur on other planets.
- Nature-related affinity magics, such as animal, plant, weather, or sea magic, show up as a metallic bronze colour.
- Anti-magic, an unusual strain of magic that destroys any other type in encounters, shows up as a metallic brass colour.
- Magic affinities related to abstract concepts such as love, thresholds, or magical signatures shows up as a metallic copper colour. Note that the magic related to magic signatures only shows its colour while in active use; once a spell is completed, the copper signature disappears. This does not apply to any other abstract affinities.
- Standard magic of the soul, which any person can learn to use (provided they actually have a soul), shows up as a metallic silver colour.
- Magic associated with celestial bodies or fae creatures shows up as a metallic gold colour.
- Craft magic associated with primarily-artistic endeavours (eg dancing, music, painting, literature) shows up as a metallic brass colour containing sparks of another single colour; the specific colour identifies which art form the magic is associated with.
- Craft magic associated with non-artistic or partially-artistic endeavours (eg carpentry, metalsmithing, glassblowing, stonecraft, weaving, etc) shows up as a metallic copper colour containing sparks of another single colour; the specific colour identifies which craft the magic is associated with.
- Elemental magic shows up as a swirl of two colours - red and orange for fire, deep blue and sky blue for water, slate grey with green threads for earth, sky blue with yellow threads for air, white with brass threads for light, and black with brass threads for darkness.
- The djinn have their own unique set of magical colours - they show up as a swirl of two solid colours in flame-like patterns. Similar to the Gift, the specific combination of colours uniquely identifies the individual djinn.
- The phoenix also a unique magical colour, a swirl of orange, yellow, and red in flame-like patterns.
- The magical force of goodness, Light Magic, shows up as pure white, while the magical force of evil, Dark Magic, shows up as pure black.
- Ritual magic typically shows up as silver or gold, depending on the ritual, though other colours are also possible - it depends on the origin of the ritual. Sympathetic magic and alchemical magic (two common cases of ritual magic) show up as bronze.
Even though all standard non-Gifted mages have a silver signature, it’s still possible to distinguish between the silver of different mages. It’s not something that can be described in visual terms; indeed, if you were to make a painted representation of the magical colours, they may well be indistinguishable. However, when they actually appear in one’s magic sight, each person’s aura has a distinct feel to it even if they happen to appear as the same colour.