To assign which parts of your vehicle receive custom colors, assign the following RGB material colors in your 3D modeling program (3ds Max, ZModeler, Blender):

Use a JSONC file (JSON with Comments) to configure the new custom vehicle colors.

📌 Path: ModelExtras/data/<FILENAME>.jsonc or modloader/AnyFolder/<FILENAME>.jsonc

Both model ID and model name are valid FILENAME (e.g. 602.jsonc or alpha.jsonc).
💡Tip: It is recommended to use model names instead of model IDs to avoid conflicts with other mods — especially when using added vehicles.

Every JSONC configuration requires a metadata specification before any other settings. See here: METADATA

➡️​ A JSONC file contains the following fields:

• "carcols" – The main object.
  • "colors" – A list of RGB color values.
  • "variations" – A list of color combinations using indices from the color list.

{
  "carcols": {
    "colors": [
      { "red": 255, "green": 0, "blue": 0 },     // Index 0
      { "red": 0, "green": 255, "blue": 0 },     // Index 1
      { "red": 0, "green": 0, "blue": 255 }      // Index 2
    ],
    "variations": [
      { "primary": 0, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 1, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 2, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 2, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 1, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 2, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 0, "secondary": 0, "tertiary": 0, "quaternary": 0 },
      { "primary": 1, "secondary": 0, "tertiary": 0, "quaternary": 0 }
    ]
  }
}

When a supported SA-MP (San Andreas Multiplayer) client is detected, ModelExtras does not register the custom carcols feature, avoiding conflicts with multiplayer vehicle color tables.