Update Theme Color

Go to public\assets\css\variables.css and search for the variable name . You can just copy the variable form there and paste it in variables.css removing the default flag and assigning a new value. For Example, here I've redefined color scheme for this theme:

Dark & Light Layout

To set the layout to dark or light just change the body class to layout-dark for dark layout and layout-light for light layout

Additionally, if feasible, would you be able to update the dark layout color in a similar manner

Update Logo

How to change logo then go to views/partials/_top_nav.blade.php

Navigation Structure

Change the navigation according to your content, also you can add or remove according to your needs then go to views/partials/_menu.blade.php

For Favicon icon

Favicon is an icon associated with the URL that is displayed at various places, such as in a browser’s address bar or next to the site name in a bookmark list.
You can add a Favicon to your Website using the following code then go to views/partials/_header.blade.php

For Changing Fonts

You can add/change the site font, from all fonts used from Google Web Font Services, with the one that suits you the best. You can find the font link in top of the Style.css in all HTML file. See example below: