function nada_theme_styles() {
    wp_register_style( 'fonts-style', '//fonts.googleapis.com/css?family=Roboto:300,700', array(), null, null );
  wp_register_style( 'nada-style', get_stylesheet_uri() );

  wp_enqueue_style( 'fonts-style' );
  wp_enqueue_style( 'nada-style' );
}
add_action('wp_enqueue_scripts', 'nada_theme_styles');

function remove_nada_theme_font_style() {
    wp_deregister_style( 'fonts-style' );
    wp_dequeue_style( 'fonts-style' );
}
add_action( 'wp_enqueue_scripts', 'remove_nada_theme_font_style' );

function remove_nada_theme_font_style() {
    remove_action( 'wp_enqueue_scripts', 'nada_theme_styles' );
}

add_action( 'after_setup_theme', 'remove_nada_theme_font_style' );

function remove_nada_theme_font_style() {
    wp_dequeue_style( 'fonts-style' );
    wp_deregister_style( 'fonts-style' );
}

add_action( 'after_setup_theme', 'remove_nada_theme_font_style' );

if( !function_exists('doctor_enqueue_scripts') ) :
    function doctor_enqueue_scripts() {
    ...
    wp_enqueue_style( 'doctor-theme-color', get_template_directory_uri() . /assets/css/color-schemes/'.$current_style.'.css', array(), '3.2' );
    ...
    }
    add_action( 'wp_enqueue_scripts', 'doctor_enqueue_scripts' );
endif;

function custom_color_scheme_theme() {
    wp_dequeue_style('doctor-theme-color');
    wp_deregister_style( 'doctor-theme-color' );
    wp_enqueue_style( 'rigenera-theme-color', get_stylesheet_directory_uri() . '/assets/css/color-schemes/custom.css', array(), '3.2' );

add_action( 'wp_enqueue_scripts', 'custom_color_scheme_theme', 100 );

add_action( 'after_setup_theme', 'custom_color_scheme_theme');