@Override
    public void write(Json json) {
        json.writeValue("colors", colors);
        json.writeValue("fonts", fonts);
        json.writeValue("freeTypeFonts", freeTypeFonts);
        json.writeValue("classStyleMap", classStyleMap);
        json.writeValue("customClasses", customClasses, Array.class, CustomClass.class);
    }
Called when project is saved to an SCMP file.
@param json
core/src/com/ray3k/skincomposer/data/JsonData.java