Color

You can specify a color property to apply to a custom machine model.

This property must be specified inside the appearance property.

The color must be an integer of type: 0xRRGGBB: go here if you don't know how to calculate an integer color from RGB values.

The color will only be applied to faces of the model that have "tintIndex": 4 specified, all other faces will be ignored and not be colored.

You can find some infos about tintIndex face property on the Minecraft Wiki

The Color property is optional.

Default : 16777215 Full white color, this will not change the texture color.

Example:

This will apply a full red color to all faces of the machine model that have "tintIndex": 4 property.

{
    "appearance": {
        "color": 16711680
    }
}