peiche/cover

<?php
/**
 * Color Posts Compatibility File
 *
 * @link https://wordpress.org/plugins/color-posts/
 *
 * @package Cover
 */

/**
 * Sets the custom CSS for the header background color,
 * plus text color overrides for the contrast
 *
 * @param string $colors_css The string that contains the output CSS.
 * @param string $color The color derived from the image.
 * @param string $contrast The black or white contrast color.
 */
function cover_use_custom_colors( $colors_css, $color, $contrast ) {
    // Reset colors.
    $colors_css = '';

    $post_id = get_the_ID();

    $tonesque = get_post_meta( $post_id, '_post_colors', true );
    if ( ! empty( $tonesque ) && is_array( $tonesque ) ) {
      extract( $tonesque );

      if ( 'ffffff' != $color ) {
          $colors_css = '
              body .header,
              body .header a,
              body .header .site-description,
              body .cover {
                  color: rgb(' . $contrast . ');
              }
              body .header a:hover {
                  border-color: rgb(' . $contrast . ');
              }
              body .header .site-description {
                  border-color: rgba(' . $contrast . ', .25);
              }
              .hamburger span,
              .hamburger span:after,
              .hamburger span:before {
                  background-color: rgb(' . $contrast . ');
              }
              body .header .backdrop {
                  background-color: #' . $color . ';
              }
              ';
      }
    }

    return $colors_css;
}
add_filter( 'colorposts_css_output', 'cover_use_custom_colors', 10, 3 );