Hi Jure,
Thank you for choose our theme and your kind words.
1. You can change color of all button by add below code to Claue > Theme Option > General Layout > Custom CSS
a.button, .jas-ajax-load a, button.button {
background: #222;
border-color: #222;
color: #fff;
}
and change #222 and #fff with your color
2. You can change footer logo in Widgets > Footer #1 and change path
http://janstudio.net/claue/demo/wp-content/uploads/2016/10/logo-2x.png
with your logo path.
Kind regards
Harry
Premium Wordpress themes and plugins, Best WooCommerce theme https://themeforest.net/user/janstudio/portfolio?ref=janstudio