Your magic majesty.
Mage slimes are not actually a type of slime, but they are just a normal slime but with magic abilities. Please treat the format like a game mechanic, because that's what it is.

Basic Magic

Mage slimes can use these spells:

Spell Effect Exclusive To?
Fire Blast Blasts fire to an enemy Fire-based slimes, boom slimes
Water Beam Shoots water at a Tarr No one
Water Shield Gives the slime a watery aura that harms Tarr, allows aquatic slimes to move outside of water and survive Water-based/aquatic slimes
Light Ball Sends a ball of light toward the enemy No one
Levitation Makes a slime levitate on top of a magic cloud No one

Master Mages

Blasting you off with the spell of light!
Master mages can use more powerful spells:

Spell Effect Exclusive To?
Fireball Shapeshifts the slime into a fireball Fire-based slimes, boom slimes
Tsunami Sends a wave of water towards an enemy Water-based slimes
Light Beam Sends a beam of light towards an enemy No one
Light Shield Produces a light so bright that whoever sees it can't see for a few seconds Slimes that produce light
Telekinesis Levitates an item or other slime on top of a magic cloud No one
Grow Makes the slime temporarily largo-sized Slimes that are not largos and not already large
Shrink Makes the slime temporarily small Largos and other big slimes
True Invisibility Makes a slime completely invisible Hunter Slimes, other slimes that can go invisible or leave existence
Wind Blast Sends a gust of wind toward an enemy, pushing them back Simes with wings, air/sky-based slimes

Dark Mages

The slime who must not be named...
Dark mages use a different, more harmful set of spells from master spells that causes havoc among slimes -and ranchers. (Note, only some of the spells are different.) They purposely attack other slimes to steal their stuff or on a full moon and are hostile toward ranchers. While they are rare, they need to be stopped when they do happen.

Spell Effect Exclusive To?
Shadow Fireball Shifts into a fireball, anyone on fire can't be extinguished with water Fire-based slimes
Storm Sends a stormcloud above a slime Water-based slimes
Shadow Beam Sends a beam of shadowy energy toward a slime No one
Disguise Disguises the slime as a harmless slime Hunter Slimes
Confusion Sends a red beam that makes a slime dizzy, and confuses them into attacking other slimes or jumping off the island No one

Variant Appearances

Variant slimes have different appearances based off their level and alignment, but all dark mages have red eyes. I will only be listing species that would normally be mages in the wild.

Species Basic Master Dark
Tabby Pale Gray White Dark Gray
Phosphor Purple Pinkish Dark Purple, Red Inner Light
Hunter Light Brown Gold Dark Gray
Boom Orange Gold Dark Purple, Red Cracks
Honey Orange Amber (light orange) Dark Brown
Puddle Light Cyan Pale Blue Dark Purple
Dragon Blue-green Blue Dark Gray, Red Inner Light
Bird Bright Blue Cyan Black