Interesting question! In the threejs reading, they make the point:

What that means is if you want your scene to fade to a certain color you need to set the fog and the background color to the same color. The background color is set using the scene.background property.

So, in our examples, we saw:


const fogColor = "lightGray";
scene.fog = new THREE.Fog(fogColor, near, far);
scene.background = new THREE.Color(fogColor);

Now, to your question about what color the fog should be. In my experience, fog typically seems to be light gray, but at night, perhaps it would make sense for the fog to be dark gray (while the scene background is black).

I personally can't think of situations where it might have a hue, but I asked ChatGPT, and it came up with some interesting suggestions:

🔥 1. Desert or Sunset Scene – Warm Fog (Orange/Yellow)

To mimic dust or sand in the air, or the warm glow of a sunset, you might use a golden or reddish hue:


scene.fog = new THREE.Fog(0xffcc66, 10, 100); // Warm desert tone

🌲 2. Forest or Swamp – Greenish Fog

To create a misty, eerie forest or swamp, use a desaturated green:


scene.fog = new THREE.Fog(0x336633, 5, 50); // Murky green

🌌 3. Sci-Fi or Alien World – Purple, Blue, or Teal Fog

For alien or futuristic environments, stylized fog in cool tones works great:


scene.fog = new THREE.Fog(0x6600cc, 20, 150); // Deep purple fog

❄️ 4. Snowy or Ice World – Pale Blue or White Fog

To make a snowy world feel cold and immersive:


scene.fog = new THREE.Fog(0xe0f7ff, 5, 100); // Icy blue

👻 5. Horror or Haunted Scene – Desaturated Blue/Green or Even Black Fog

For a spooky vibe, try darker or odd-toned fogs:


scene.fog = new THREE.Fog(0x111122, 2, 30); // Creepy bluish-black