Changing color on one single nav bar page

I’m trying to have the “shop” page on my nav menu (not the button) with a different color, tried this css but is not working 

nav.Header-nav [href="shop"] {
  color: #709E96 !important;
}

url: https://cantinalepietre.com

any help?

Use this new CSS code for both desktop + mobile

.header-nav-item:nth-child(6) a, div.container.header-menu-nav-item:nth-child(6) div {
    color: #cb1717 !important;
}