Center logo in Parallax One

If you want to center the logo in Parallax One or Parallax One Plus then you need to install the plugin  Advanced CSS Editor and in Appearance -> Customize -> Advanced CSS Editor, click on the Desktop icon make sure the text then says "Desktop CSS" and add the following snippets of code. Do the same thing for tablets by clicking the tablet icon, make sure the text then says "Tablet CSS" after clicking and add the following snippets of code:

.navbar-header {
    width: 100%;
    display: flex;
    justify-content: center;
}
.main-navigation ul {
    display: flex !important;
    justify-content: center !important;
}

Click save and publish and you're done.

You can find a few examples of websites using Parallax One and a centered logo on this showcase: A Showcase Gallery of Awesome User Sites Built with Parallax One.