View file StuffPost/stuffpost/functions/customizer/panel-colors.php

<?php

//main
	$wp_customize->add_setting( 'main_color', array( 'default' => '#49c5b6', 'sanitize_callback' => 'sanitize_hex_color' ) );
	$wp_customize->add_control( new WP_Customize_Color_Control( $wp_customize, 'main_color', array(
	  'label' => esc_html__('main color', 'stuffpost' ),
	  'section' => 'colors',
	  'settings' => 'main_color',
	) ) );

//meta
	$wp_customize->add_setting( 'meta_color', array( 'default' => '#b3c2bf', 'sanitize_callback' => 'sanitize_hex_color' ) );
	$wp_customize->add_control( new WP_Customize_Color_Control( $wp_customize, 'meta_color', array(
	  'label' => esc_html__('meta color', 'stuffpost' ),
	  'section' => 'colors',
	  'settings' => 'meta_color',
	) ) );

//white_color
	$wp_customize->add_setting( 'white_color', array( 'default' => '#FFF', 'sanitize_callback' => 'sanitize_hex_color' ) );
	$wp_customize->add_control( new WP_Customize_Color_Control( $wp_customize, 'white_color', array(
	  'label' => esc_html__('white color', 'stuffpost' ),
	  'section' => 'colors',
	  'settings' => 'white_color',
	) ) );

//black_color
	$wp_customize->add_setting( 'black_color', array( 'default' => '#2a2a2a', 'sanitize_callback' => 'sanitize_hex_color' ) );
	$wp_customize->add_control( new WP_Customize_Color_Control( $wp_customize, 'black_color', array(
	  'label' => esc_html__('black color', 'stuffpost' ),
	  'section' => 'colors',
	  'settings' => 'black_color',
	) ) );