Wanted to make Arcie be able to cast ANY colour of fire, so I made this handy chart to illustrate that :)
The area of the wheel marked with dark red indicates flames whose colour is determined by its absolute temperature. The number shown inside this region represents the temperature in degrees Kelvin. This closely follows IRL laws of black body radiation, where the wavelengths of light an object emits is determined by its temperature. This is not followed for temperatures below 800°K.
In general, as intensity of a flame increases, its colour gets lighter. This does not apply to flames which follow black body radiation.
Verdant flames - A type of fire imbued with the power of nature. Can heal when at low intensity, albeit this healing is somewhat weak. Spreads faster than other flames, and can somewhat resist water.
Gamma flames - A type of flame imbued with low amounts of high frequency radiation. Deals high damage, has a chance to poison the target, and a very low chance to cause a random mutation. Requires a lot of energy from the caster.
Frostfire - This flame, when touched, actually has a sensory effect similar to freezing, despite being hot. Despite being hot, it can still cause the target to freeze, although they can thaw rather quickly.
Spectral flames - A class of fire which is comprised of tormented souls, forever wandering the cosmos. Very effective at flinching opponents due to shock.
Serene embers - Flames which can quickly calm those hit by it, dealing no damage and dispelling anger for a short while. Is ineffective on a target when used repeatedly on that target.
Aquatic flames - A contradictory type of flame which harnesses the elemental power of water. Highly effective at converting other flame types to Aquatic flames, and can disperse through water.
Mystic flames - Not much is known about these flames, which appear to flicker in and out of existence in curled, short-lived wisps of fire. Deals somewhat high damage and has a chance to confuse those hit by it.
Corrupted flames - Flames which carry the greed of ill-minded rulers. Spreads very easily and burns very tall. Has a low chance to confuse targets when they are in contact with the flame for more than 5 seconds.
Faeflame - Flames which have been imbued with magical fairydust and visually shine much more than other flames. Can relieve negative statuses if cast with an extremely low intensity.
Astral flames - Flames imbued with the power of stardust that explode in a starry, glittery nebula when touched. Deals high damage and can shortly stun.
Heat of Love - A class of flames often not used in combat, but for other purposes. Easily seduces a target for around 30 minutes, loses potency if used on the same target repeatedly.
Solar flames - Flames which borrow power from a nearby star, containing high amounts of charged particles. Gets faster the longer it travels, and can cause paralysis. Requires a decent amount of energy from the caster.
Heavenly flames - A class of flame which borrows power from Arceus, being very powerful but also requiring insane amounts of energy to cast. It is also extremely bright and can easily cause temporary blindness.
Cursed flames - A type of flame which cannot be put out by water or a lack of oxygen - only the wielder can put this fire out. Deals very high damage.
Abyssal flames - A forbidden class of flame which uses dark matter to achieve insane power levels. Depletes lots of energy from the caster, and has a weak gravitational pull.