{ contrast } on focus

Hi,
I'm helping a friend freshen up her site. She'd like to keep her colour
palette light and airy.

Is it acceptable to have links in the navigation not meet contrast until it
gains focus? I've seen orgs like Google do this but it doesn't mean it's
correct and I'd like to be sure.

On a related note, could a link be considered disabled until it gains
focus? I'm wondering if that's why google opted to do this.

Thanks I'm advance!