My final CSS looks like this – i am sure it could be cleaner but it works in case anyone else is looking for a fix. I removed the old lines that made the search active as this was already selected in the customiser.
.navigation-search input[type="search"]:focus {
background: rgba( 255,255,255,1); /* set bar to 100% white */
color: rgba( 0,0,0,1); /* set font to black */
font-family: "Amaranth"; /* changed font */
font-size: 30px; /* increased font size */
opacity: .99; /* increased opacity to almost max */
}