Graham
bemethavinci <div class="w3-bar w3-red ">The footer</div> is a basic bar you could use
look in the code w3css uses named colors in the classes (ie: w3-red) just change them
The body colors are not set at all so either give the <body> tag a color class or set your own styles for the body in a custom style sheet
Twig is a lot of work but the same as for any other template most of it is just change the class names
you don't even have to change them all or delete the old ones just add the new classes
everything is in the docs with examples
You could even have one of the xtgem css templates on the site as well as the w3css then you don't have to change the blog twig at all
like this
http://cssw3s.xtgem.com/blog
