Border Underline in Header Nav

Hi, all!

I'm trying to add a colored bottom border to my header nav links. I've successfully coded the border, but my problem is that it inherits the text color, rather than the independent color I've coded in. Any thoughts as to what might be happening? Thanks! Code is below. 

//HEADER NAV UNDERLINE//
.header-nav-item a {
  display: inline-block;
  color: #FFFFFF !important;
  text-align: center !important;
  border-color: #627360 !important;
  border-bottom: 2px solid !important;
}

Thanks in advance for any input!