Hi there,
This particular button is styled with custom CSS found on your site’s Appearance > Customize > Additional CSS.
It’s this line:
/* navigation contact button */
.main-navigation:not(.slideout-navigation) .main-nav li.nav-button a{
color: #ffffff;
background-color: #8eb2a6;
line-height: 44px; /* button height */
padding: 0px 22px; /* space inside button */
margin-top: 4px; /* adjust to horizontally align with other menu items */
border-radius: 40px;
margin-left: 22px; /* space to the left of button */
transition: all 0.4s ease 0s;
}
You can change the background value and the color value of this CSS to your preference.