Biome Tinter is a client side mod that lets you set the sky, fog and lighting colour of every biome in your pack, and fades between them smoothly as you walk across the border.

Built for personal use because i wanted my modpack's biomes to actually feel different from each other, but feel free to use it in your own packs!

Every biome starts switched off, so installing this changes nothing until you decide what you want to look different.

Features

Per biome sky colour, fog colour, and lightmap tint
Smooth crossfades between biomes instead of an instant swap, with a configurable fade length
Colours release at night on vanilla's own darkening curve, so your bright desert sky doesn't glow through midnight
Live config reload, edit a colour while the game is running and watch it fade in about a second later
Fully client side, works on any server including vanilla ones, nothing to install server side
Every biome in your pack gets an entry generated automatically, modded ones included
Config is split into one file per mod, so your Biomes O' Plenty edits don't live in the same wall of text as your vanilla ones
Lightmap tint can follow the sky colour or be set on its own, for when you want a red sky without red ground

Configuration

Join a world once and the mod writes config/biometinter/, one .toml per mod that adds biomes, plus a shared settings.toml.

Each biome looks like this:

["minecraft:desert"]
    enabled = true
    skyColor = "#CEB97C"
    fogColor = "#E4CC97"
    lightmapTint = "#F3EDDD"

Set enabled = true and give it a hex colour. Leave a field blank and that channel keeps its vanilla colour. Leave lightmapTint blank and it follows whatever the sky is doing, which is usually what you want.

settings.toml holds the global knobs:

enabled is the master switch, false turns everything off without touching your per biome work
transitionTicks is how long a fade takes, 60 by default which is 3 seconds. Drop it to 10 while you are picking colours so you aren't waiting around between edits
liveReload watches the folder and applies your edits without a restart, on by default

biomeBlendRadius and smoothCurve are in the file but do nothing yet, they are there for later.

Editing colours while playing

Open the toml in any text editor with the game still running, change a hex, save. About a second later the sky fades to it.

Two things worth knowing: stand in the biome you are editing, since the fade applies to wherever you currently are, and run /time set noon first, because the override backs off as the sun goes down and you will be chasing a moving target at dusk.

If your editor's save doesn't seem to land, run /biometinter reload. Some editors write through a temp file and rename it, which can slip past the watcher.

Commands

/biometinter reload reloads the config from disk by hand
/biometinter status tells you what is actually loaded, entry count, fade length, and whether live reload is on

Both are client commands, so they need no permissions and work on servers that don't have the mod.

Requirements

Nothing besides this mod!

Notes

Colours only apply to the biome you are standing in, this is a tinting mod and not a shader, so don't expect it to change how a distant biome looks from a mountaintop.

Performance cost is effectively zero. There is no world generation, no entities, no packets, and nothing registered into the game's registries.