The Header options are found in
header-options.php and apply to all areas above the main navigation menu on each page. The main navigation menu (the Navbar) is actually now optional.
There are a number of options for the header.
Firstly there is a 'textarea' where you can define a banner to be displayed at the top of every page. You can use this for any purpose you see fit, though it is anticipated it will be left blank most of the time. Any text entered will be displayed 'as is' inside a full width
<div> which is styled as browser default sized orange text on a black background with white links and some padding. So if you want to use HTML then great, but plain text will do something sensible too.
The second option was added in version 3.4.4 and is not shown in the screen grab above which comes from version 3.4.0. It gives the option of having an instance of the Navbar at the very top of the header. This is disabled by default.
The second option that is shown in the screen grab was removed in version 4.0 of the theme. The Scout Association logo was displayed in purple on white and the latest brand guidelines no longer illustrated it in any other colours. Previously the guidelines did illustrate alternative colours and these were made available in the theme. The 2018 brand guidelines allow, or indeed require, the logo to appear in regional colours so version 6.0 of the theme reintroduces this option (all the logos are on a white background so just the foreground colours are listed).
From version 4.0.3 of the theme another option has been added. It allows you to specify the ID of an image in your Media Library that will be used instead of the default logo. The default logo was 98x69 pixels which seemed rather an unusual size and was perhaps one of the last remnants of the Scouts 4 WordPress theme. In also included white space top and bottom that isn't in the official logo. For version 4.0.4 of the theme the logo was regenerated from the official version and resized to 100x62, with the CSS adjusted to maintain the exclusion zone around the logo. The theme will expand the height of the header if your custom logo is higher than the default. Your logo is not being resized so if it is much more than 100 pixels wide things may look odd.
Two more options were added in 4.0.4. The logo is implemented as a CSS background with an default offset of 10 pixels horizontally and vertically to maintain the exclusion zone around the logo. This might not work so well for your own logo and so this offset can be overridden. For example on this documentation site the logo looks better with the horizontal offset set to 0 to align it on the left. It also works better with the vertical offset set to 0 too.
The next four options are related to the default display of your Group name (or other title) and a tagline alongside The Scout Association logo. You can override this using your own template file (see the Header section), in which case these options only have any effect if you have chosen to use them for your own purposes.
The first of these options allows you to specify your Group name (again it could be a District, County or other unit name, or indeed anything you choose). The default is the WordPress blog name but that isn't necessarily what you want in the header. For example '1st Trumpton' is a reasonable name for a blog but the brand guidelines tend to favour that being shown as '1st TRUMPTON' when used as a heading so that could be entered here. There is also a drop down menu to allow you to choose one of the Scout brand colours for the name. Using purple or green is probably the best from a branding point of view, but one of the others would be acceptable. The default is green.
The 'tag line' that goes under the Group name is read by default from the blog description. If that is empty or a known WordPress default it is set to a suitable generic tagline for the Scouts. The next field allows it to be overriden by the Theme Options, just to keep things together, and the colour can also be set to one of the brand colours. The default is purple.
The last option controls whether the Navbar is displayed at the bottom of the Header, as it is on this documentation site. The default is to show it but the theme works fine without it, although you'll have to make sure you arrange alternative methods of navigating the site (such as enabling the optional Navbars at the top of the Header or Footer, or using a WP Navigation Menu in one of the size predefined locations.