Add colors to existing color palette without replacing it
You can merge palettes $existing = get_theme_support( ‘editor-color-palette’ ); $new = array_merge( $existing[0], array( array( ‘name’ => __( ‘Strong magenta’, ‘themeLangDomain’ ), ‘slug’ => ‘strong-magenta’, ‘color’ => ‘#a156b4’, ), array( ‘name’ => __( ‘Light grayish magenta’, ‘themeLangDomain’ ), ‘slug’ => ‘light-grayish-magenta’, ‘color’ => ‘#d0a5db’, ), )); add_theme_support( ‘editor-color-palette’, $new);