My health potions are green and poisons are red

See also: video game AOE FX.
Big glowy green area? Could be a healing aura, could be poison. Good luck!
- Nah this one is easy.
  If it's green and sparkly, it's a good thing. If it's green and bubbly, it's a bad thing.
  
  Given what Mountain Dew has done to me, that tracks.
  
  Green w/ sparkly bubbles = Happy Drunk
- Or radiation perhaps?
  
  Or acid!
  
  I like the fallout approach
  Green glow: radiation
  Brown water: radiation
  Bottled Water: Good!
  Not really, believe it or not, radiation. (You must be thinking of purified water)
- Purple: Magic??
  Green: Life/death??
  Red: Life/fire??
  Blue: Magic/cold??
  Honestly the only colour I don't feel uncertain about is orange, that's always bad.
  Also on the topic of health potions, a great piece of advice I once heard was that if your players are in a foreign land, remove health potions. Give them health biscuits and watch them reconcile with God.
  
  Orange is machinery/technology
  
  FFXIV the stack markers are close to orange... and long time ago it had Bard having a fire circle that damaged enemies but not allies, yet the tanks thought it was bad and would drag enemies out of it. Probably why they removed that one.

Bright red barrel of aircraft grade fuel.
Shoot it.
Spawns a leak.
//FPS players mind's implode//
- Toss a lighted match into the growing puddle.
  Match goes out.
  
  Shoot it directly with a flamethrower.
  Puddle burns slightly like a gas stove before going out again.

How about Oblivion where every potion, including drugs, are red?
- FWIW, potions are drugs.
  
  except the ones made from potatoes and cheese, those are just soup

I color code all my info. (..) Green means go, so I know to go ahead and shut up about it. Orange, means orange you glad you didn’t bring it up. Most colors mean don’t say it.
Michael Scott

Electric element. Team Yellow vs Team Blue, FIGHT!
- There is (was?) an electric power provider in Germany by the name of Yellow. Their whole marketing was "electricity is yellow!"
- what do you mean? electricity is purple
- Electricity is yellow.
  Blue would be water.
  What game would actually use blue?
  
  Blue-white lightning icons/symbols are quite common, I would think.
  Slay the Spire comes to mind:
  Then again, there are some yellow ones, too:
  
  Crackly blue is water? I'd even think ice before water.

"There are no 'rules' for fantasy"
Wrong. To write good Fantasy (of SciFi), you have to go through a process called "World Building" where you lay down the rules of your world. Properly done, the amount of World Building exceeds the actual works by far. It is absolutely necessary to create a core of inner logic to the story. You are not bound by the rules of our world, yes, but you are bound by the rule of consistency. If you violate those, you automatically write crap Fantasy (or SciFi).
Funny, though, that e.g. many literature teachers / professors don't even know about the idea of World Building.
- A clearer way to phrase it might be "there are no rules for the genre of fantasy". An individual world needs self-contained rules, yes, but just because Tolkien's Dwarves have beards regardless of gender doesn't mean that your Dwarves need to be the same.
- That's hard fantasy. Soft fantasy can be good too.
  
  Can, yes, but in my experience rarely is.
- To write good Fantasy (of SciFi), you have to go through a process called “World Building”
  I think this is more implying that you don't have to work from the same framework for every fantasy world. Not everything has to be set in Arthurian Medieval Times with Crusader-Era social sensibilities. The menagerie of mythical creatures isn't a prerequisite or delimiter (dragons / unicorns / etc are not a requirement nor are robots / cthulhoid horrors / woolly mammoths disallowed). You need internal consistency (to a degree) but you aren't forced to adhere / omit any genre trope.
  I would say, at an absolute bare minimum, you need some kind of fantastical or supernatural element to make it "Fantasy" as opposed to "Historical Fiction" or "Science Fiction" or some other category of fictional prose. Although, the genre of "Magical Realism" does make even that distinction a bit fuzzy.
  many literature teachers / professors don’t even know about the idea of World Building
  You don't necessary need to go through the whole work of World Building if you're just banging out a short story or novella. Even serial writers don't necessarily bother going deep on the background material until they feel the need to expand the scope of the setting. I mean, look at the Star Wars setting. George Lucas didn't have Jabba the Hutt defined as a big slug monster until the third movie. In the original film, there was a cut scene in which Han confronts Jabba, who was just a be-feathered chubby gangster.
  If you're just spitballing or cranking out bits of fiction in brief, World Building can be superfluous. A story that takes place entirely in a single house over the course of a long weekend doesn't need the kind of scaffolding that a Long Walk to Mordor requires.
  
  George Lucas is the perfect example what happens when you don't do world building. The Star Wars universe is basically just retcons stacked onto other retcons.
  And I am a firm believer that even short stories in a fantasy or SciFi setting don't work without at least a certain amount of world building.
  The number of fantasy and SciFi stories where the author thought they could get away without thinking their world through and which ended up badly is amazingly high.
- Also the important rule here is everything not explained to be different is assumed to be the same as our understanding of the real world.
  
  That is part of world building, too. If your fantasy world needs more explaining than storytelling, something is seriously wrong.
- Crap fantasy is still fantasy. Had a great time coming up with bad fantasy stories in my childhood when I knew nothing about good writing. Art is what you make it.
- Rules for fantasy writers.
  For a post centered on reading, the actual comprehension of what is being said in this thread is poor.
  
  Why do you imagine that the,post is about reading?

Nethack (and derivatives) is pretty much the only game I know of where the health potions may or may not be red.
And I guess Dark Souls... It's more of an orange than a red. But maybe that's just the color of the flask. Idk what the substance inside looks like. 🤷🏻‍♂️
- the flask is green! i would know since i emptied it one too many times snd the texture is dark green
  
  Then the insides have to be red for it to appear orange through green glass. The health potion is red!

Why should your fantasy game be limited by something like "health". Whether you die should be based on vibes.
- DM: Roll a Vibe Check
  Player: I rolled Dark Green
  DM: Ooohhh...
- My vibe is slightly hurt with a hint of mental damage
- Why should your fantasy game be limited by something like “health”.
  One way of escalating drama and tension is by injuring a main character. The scene in Terminator 2, where Sarah Connor has to knock the T-1000 into the blast furnace with consecutive shotgun blasts, isn't nearly as cool without her doing it with a wound in her arm. Frodo collapsing from exhaustion gives us the incredible moment of Samwise shouldering him and carrying the guy, ring and all, up the slope of Mt. Doom.
  And particularly for folks invested in the coolness of their characters, some conflicts are much more fun when the outcome isn't anything either storyteller or player could have anticipated. A totally unexpected David v Goliath moment, where a scrawny guy fells a giant with a lucky shot, will be the kind of story people talk about for years - whether David or Goliath or both are PCs.

Similarly to how paprika chips come in blue bags and salted chips come in red bags. Anything else is heresy. Unless you live right across the border, where it's exactly the opposite.

Overlord the anime has a whole arc about the protagonist using his immense power and influence to have people start research on how to turn blue potions red.

My health potions are red, also, pulp free is not an option. >:)
- The pulp is from fruit, right? The pulp is from fruit, right!?
  
  ... yes^tm

I hate dragons. Controversial take but like just come up with some other mystical creatures! have some fun with it! if rather interact with a pink unicorn plushie than fight another dragon
- Granted.
  Anthrax the Destroyer is how hiding among stuffed animals.

Reminds me of that overwatch character with the yellow healing aura and the green speed aura. Just why?
- Because his default coloring is green and yellow I'd guess
  
  Yeah but the healing aura should be green and the speed one should be yellow
- In Overwatch, healing is consistently represented by the color yellow. Mercy's beam, Ana's darts, Moira's piss, Soldier's healyboo, etc. Making Lucio's speed aura yellow and healing aura green would be visually confusing
  
  Then the entire game is wrong.

It's true.
Rules are meant to be broken - apart from when they aren't.
You can change any aspect of the world any way you like, but only if doing that is critical to your universe and story.
Messing up without reason conventions that are well established is a dick move, unless the whole point of your work is to screw with people.
- Also you need to consistently break conventions once you do it or you really screw with people and make a shitty world.

I used yellow for health to avoid red/green colourblind issues
- I love the possibility of having a red/green colorblind character and having to roll to hopefully pick the right potion when they both health potion and poison in their bag.
  
  But poison is purple. It's acid they'd get it mixed up with.
  
  I feel like any decent adventurer would develop a system. I hear blind people will fold their paper money a certain way so they can differentiate between the different values...
- I'm not sure if that's a joke? If you have red/green colorblindness, you wouldn't be able to distinguish yellow either. You'd just see blue and not blue.
  
  https://davidmathlogic.com/colorblind/
  https://color.adobe.com/
  You can use this to come up with a palette, mine was safe

Daggerfall!

Why not both?

Not sure if this is more or less of a problem for people wtih red-green colorblindness.
On the one hand, it's harder to differentiate at all. On the other hand, it kind of removes that established expectation and keeps you in the habit of adapting.

Looking at you, "Dragon Age" Veilguard.

The old TSR/SSI game Unlimited Adventures had randomized potion colors. It's also how I learned that khaki is not pronounced 'kahiki' when trying to explain what was going on to someone (I knew khakis as a type of trouser not a color).
https://en.wikipedia.org/wiki/Forgotten_Realms%3A_Unlimited_Adventures
Edit: or maybe I'm thinking of another gold-box game if that one didn't have some random generation. Hrm.
- Pixel dungeon does the same thing, you don't know when you start a run what any color potion does. So they're randomized.