Wrong backgroundColor validation

[SergiuSavva]

backgroundColor - The article's background color, defined as a 3- to 8-character RGBA hexadecimal string; e.g., #000 for black or #FF00007F for red with an alpha (opacity) of 50%. Defaults to white

src/Document/Styles/DocumentStyle.php

if should be
https://github.com/chapter-three/AppleNewsAPI/blob/master/src/Document/Styles/DocumentStyle.php#L67

  protected function validateBackgroundColor($value) {
    if (!$this->isHexColor($value)) {
      $this->triggerError('backgroundColor is not valid');
      return FALSE;
    }
    return TRUE;
  }

[RajeevChoudharyNBC]

What is the alternate for this issue, as removing the setDocumentStyle makes it impossible to implement DocumentStyle class to add backgroundcolor for the article.