Dark Grey Metallic

{
    "dark_gray_metallic": {
        "class": "custom",
        "name": "Dark Grey Metallic",
        "baseColor": [
            0.3,
            0.3,
            0.3,
            1
        ],
        "metallic": 1,
        "roughness": 0.65,
        "clearcoat": 1,
        "clearcoatRoughness": 0.06
    }
}