要查找页面的HTML代码，我们可以使用IE或Chrome F12开发人员工具.

To find the HTML code of the pages, we can use IE or Chrome F12 developer tools.

默认情况下，SharePoint使用母版页seattle.master，如果要隐藏标题并更改页面标题的颜色，则可以使用SharePoint Designer 2013在此母版页的标记中添加以下样式.

By default, SharePoint use the master page seattle.master, if you want to hide header and change color of pages title, you can add the following style into tag in this master page using SharePoint designer 2013.

<style type="text/css">
#O365_NavHeader,#suiteBarDelta{
    display:none;
}
#pageTitle,#pageTitle a{
    color:green !important;
}
</style> 

如果您使用SharePoint Online现代网站，我们可以创建一个自定义主题.以下文章供您参考.

If you use SharePoint Online modern site, we can create a custom theme. The article below for your reference.

品牌化SharePoint现代网站