Barbarian - Promarily red, secondarily green. They use their emotions to tap into primal powers.
Bard - blue, red, and green They are scholars of a kind, but they study the lore of nature, and perform magic through, well, performance and affecting the emotions of those who hear them.
Cleric - white or black, sometimes with the addition of blue. They are healers who perform magic through religious ritual in service to deities which can be either altruistic or egoistic. Sometimes they are also preservers of knowledge.
Druid - primarily green, sometimes adding black or red. Spiritual guides tied to the magic of the natural world, generally existing outside of settled societal structures. Sometimes leaning into cycles of life and death and/or raw ecstatic experience.
Fighter - Any, but most commonly white or red and least commonly green or blue. Fighter is such a broad archetype, it can fit pretty comfortably into any of Magic’s color identities, but blue’s focus on knowledge and green’s focus on the natural world are the least intuitive fits.
Monk - primarily white, sometimes with some blue or red. Monks gain their skills from discipline and focus, which is white, and can lean into blue through meditation and inner-calm, or red through dedication to physical training. Or both.
Paladin - Primarily white, can be secondarily any other color. Their power comes from oaths, which is as closely tied to white’s theme of community and order as it gets. However, those oaths can range widely in their ideals and tenants; the traditional Devotion Paladin is mono-white, the Vengeance Paladin is white and either red or black (or both), the Ancients Paladin is white and green, the Oathbreaker and Conquest Paladin are white and black. Blue is, again, the least intuitive fit, but an oath tied to the pursuit of knowledge could pretty easily be devised, I think.
Ranger - Primarily green, secondarily white or sometimes black. They are nature survivalists first and foremost. Sometimes with the addition of being bastions of civilization against the chaos of the natural world, which is where white can come from. Sometimes they’re solipsistic lone wolves, which brings in the black.
Rogue - Usually black, sometimes red, often both, and sometimes blue. Rogues have a strong association with criminality which ties them to black, but some rogues are more “dashing treasure hunter” than actual thief, which leans more towards red. Some rogues mix in some blue, when they’re in the dungeon exploration business to discover lost secrets of the past, or doing the “spell thief” shtick.
Sorcerer - Primarily red, occasionally with secondary black, white, or blue tendencies. Sorcerers possess magical power, stemming from within, tending towards less subtle, often chaotic applications, all of which is strongly red. Some sorcerers also lean into solipsistic angst which brings in black, some seek to understand their magic which brings in blue, and white is mostly just to cover the bases with divine soul sorcerers.
Warlock - primarily black, sometimes green, blue, or red. Deals with demons/devils are strongly associated with black in M:tG, and while warlocks can make pacts with all sorts of entities, they all tend to carry “deal with the devil” baggage. They tend to be highly individualistic as well, which is also black, though might touch on red a bit as well. Green if they lean more into the fey/witch vibes, blue if they made deals for forbidden knowledge or secrets.
Wizard - always blue, but can be secondarily any other color. Wizards get their magic from dedicated study, which is as blue as it gets. Beyond that though, their particular form of magic can branch out into just about anything, and their motivations can be extremely varied. Green is the least intuitive fit, because green’s nature focus clashes with blue’s civilization focus, but it absolutely can be done. D&D’s specific “wizards can’t do healing” sacred cow also makes white a less obvious secondary color than black or red, but there is more to white than healing, so it still totally works, especially for abjuration wizards.
