Pacific Template: How to add CTA Button in Nav?

Site URL: https://seagroverehab.com

We are using the Pacific template; I am having difficulty using CSS code I found in other threads to make the "Schedule a Discovery Call" in our top nav be a CTA button. Anyone know if it can be done and how? We don't have a secondary nav option that I've seen in some tutorials. 

If a button isn't possible, it is possible to have "Schedule a Discovery Call" in a different font color than the others using Code? (It isn't possible in Site Styles.)

Thanks!

Add to Home > Design > Custom CSS

header#header [href*="calendly.com"] {
    background: white;
    color: blue;
}

Thank you, tuanphan! That worked perfectly. Do you know how I could make the font color change on the button to either Gold rgb - 166, 121, 069, hex - #A67945, or Teal rgb - 036, 081, 082, hex - #245152?

I tried:

header#header [href*="calendly.com"] {
    background: white;
    color: #245152;
} 

But it didn't change it.

5 hours ago, SRP said:

Thank you, tuanphan! That worked perfectly. Do you know how I could make the font color change on the button to either Gold rgb - 166, 121, 069, hex - #A67945, or Teal rgb - 036, 081, 082, hex - #245152?

I tried:

header#header [href*="calendly.com"] {
    background: white;
    color: #245152;
} 

But it didn't change it.

header#header [href*="calendly.com"] {
    background: #fff;
    color: #245152 !important;
}
header#header [href*="calendly.com"]:hover {
    color: #efece5 !important;
}

Brilliant! Thank you so much for all your help!!