I've developed a cosmetic system to illustrate a potion’s appearance using 3 basic characteristics: 1) Color, 2) Transparency, 3) Light Intensity. The system requires the 3 things we know about any given spell when converting it into a potion: 1) Arcane School, 2) Spell Level, 3) Caster Level.
Creating a potion is a magical feat drawing from a specific arcane power outside of chemistry. Even the Alchemist Class is "infusing these substances with magic siphoned from his aura". Therefore, a potion’s base color should depend on the Arcane School from which the spell comes from. Each of the Classic Arcane Schools of Magic are assigned a primary or secondary color by the GM (including White and Black).
*See Potion Color Theory at the end.
1) Color = Spell School:
Additive Colors (using light from energy) are assigned to each of the Classic Arcane Schools of Magic. The assignments I used are based on Magic the Gathering's mana color theory (with the exception of Magenta and Yellow), but it’s up to the GM to arrange the colors as he or she sees fit.
- Abjuration = White
- Conjuration = Green
- Divination = Blue
- Enchantment = Magenta
- Evocation = Red
- Illusion = Cyan
- Necromancy = Black
- Transmutation = Yellow
2) Transparency = Spell Level:
The Spell Level illustrates liquid density and how well you can seen through the liquid. This could imply texture if you desired.
- Spell Level 0 = Near Clear (appears watered down)
- Spell Level 1 = Transparent (as colored water, like apple juice)
- Spell Level 2 = Translucent (a clouded liquid, like lemonade)
- Spell Level 3 = Opaque (cannot see through it, like milk)
3) Light Intensity = Caster Level
Potions hold a charge of energy. Regardless of their glow, the arcane light of the imbued liquid does not provide sufficient illumination to improve visibility. This cosmetic feature is not meant to be used as a light source, though you could locate a potion in the dark if line of sight is not obscured.
- Caster Level 1 = Dim
- Caster Level 5 = Soft
- Caster Level 10 = Glowing
- Caster Level 15 = Bright
- Caster Level 20 = Brilliant
Issue: Identifying Potions the Wrong Way
This visual system is not meant to replace Detect Magic when identifying potions, but simply to add more depth for those who appreciate the Craft. The Alchemist Class does not require Detect Magic to identify potions, but he would take note of the physical characteristics in his Skill Check.
A character without the proper Alchemical or Arcane Knowledge would not be able to discern the meaning of the various physical properties of a potion. If it becomes an issue for the players, the GM should ignore the physical description until the potion can be properly identified as the game intended.
Potions aren't normally labeled, but every player knows how to distinguish their own stock due to its physical features. This system just helps to illustrate it.
Potion Color Theory: Additive Colors of Light
The Color Wheel has its foundation in 3 Primary Colors: Red, Yellow, Blue. From these, the Secondary Colors can be created: Orange, Green, Violet. The Wheel is used for mixing pigments, but it is not effective for mixing light.
The Additive Color scheme exists for mixing colors made of light. This is appropriate for illustrating arcane energy since light is a type of energy. Additive Colors use a different set of Primary Colors: Red, Green, Blue (RGB). From these, the Secondary Colors can be created: Cyan, Magenta, Yellow (CMY).
When the 3 Primary Colors (RGB) are combined, they create the appearance of White. When the 3 Secondary Colors (CMY) are combined, they subtract light, creating the appearance of Black. This is different from the classic Color Wheel because White and Black are naturally created by light, while those colors must be manually added to the Wheel.