inc/customizer/colors.php
public function color_overlay_transparency( WP_Customize_Manager $wp_customize ) {

		$wp_customize->add_setting(
			'hero_image_color_overlay',
			array(
				'default'           => $this->get_color_overlay_transparency_default_value(),
				'sanitize_callback' => 'absint',
				'transport'         => 'postMessage',
			)
		);

		$wp_customize->add_control(
			'hero_image_color_overlay',
			array(
				'label'           => esc_html__( 'Hero Background Overlay', 'rock' ),
				'description'     => esc_html__( 'Control the color overlay transparency when using a custom Header Image.', 'rock' ),
				'section'         => 'colors-header',
				'priority'        => 20,
				'active_callback' => 'rock_has_hero_image',
				'type'            => 'range',
				'input_attrs'     => array(
					'min'  => 0,
					'max'  => 100,
					'step' => 1,
				),
			)
		);

	}
public function color_overlay_transparency( WP_Customize_Manager $wp_customize ) {

		$wp_customize->add_setting(
			'hero_image_color_overlay',
			array(
				'default'           => $this->get_color_overlay_transparency_default_value(),
				'sanitize_callback' => 'absint',
				'transport'         => 'postMessage',
			)
		);

		$wp_customize->add_control(
			'hero_image_color_overlay',
			array(
				'label'           => esc_html__( 'Hero Background Overlay', 'rock' ),
				'description'     => esc_html__( 'Control the color overlay transparency when using a custom Header Image.', 'rock' ),
				'section'         => 'colors-header',
				'priority'        => 20,
				'active_callback' => 'rock_has_hero_image',
				'type'            => 'range',
				'input_attrs'     => array(
					'min'  => 0,
					'max'  => 100,
					'step' => 1,
				),
			)
		);

	}
public function color_overlay_transparency ( WP_Customize_Manager $ wp_customize ) { $ wp_customize -> add_setting ( 'hero_image_color_overlay' , array ( 'default' => $ this -> get_color_overlay_transparency_default_value ( ) , 'sanitize_callback' => 'absint' , 'transport' => 'postMessage' , ) ) ; $ wp_customize -> add_control ( 'hero_image_color_overlay' , array ( 'label' => esc_html__ ( 'Hero Background Overlay' , 'rock' ) , 'description' => esc_html__ ( 'Control the color overlay transparency when using a custom Header Image.' , 'rock' ) , 'section' => 'colors-header' , 'priority' => 20 , 'active_callback' => 'rock_has_hero_image' , 'type' => 'range' , 'input_attrs' => array ( 'min' => 0 , 'max' => 100 , 'step' => 1 , ) , ) ) ; }
Add setting and control for the hero image color overlay transparency.

@action customize_register
@since  1.0.0

@param WP_Customize_Manager $wp_customize
Add setting and control for the hero image color overlay transparency .