Individual button colors in navigation

Site URL: https://cxlife.org/

I have two buttons linked in secondary navigation, one for Login and one for Join. I would like them to be different colors...Login should be dark blue, and Join should remain as orange. The template is Brine (Stella).

Does anyone have a suggestion for the code?

Thank you!

Add to Home . Design > Custom CSS

.Header-nav-item[href*="sign_in"] {
    background: darkblue !important;
}