so if I can figure out how to use css to recenter the header just like you did with the color, would that solve the issue?
yep :)
And is inlining good or bad for optimization and speed?
if the amount of CSS is not to huge, it's good. if there's a lot of CSS inlined (e.g. if your HTML goes from 45kb to 120kb), then it's bad. also depends on your site's bounce rate really; if people on average view multiple pages, then not inlining is better because that way the CSS-files can be served from the browser cache as from the 2nd visit.