Menu Color

If you have a look at the theme’s stylesheet – style.css – you’ll find the relevant section, which I’ve pasted below.

Don’t edit the theme files directly, otherwise your changes will be overwritten when the theme is updated.

An easy way to add custom CSS is to install the Jetpack plugin and activate the Custom CSS module. You’ll then add your custom CSS in the new stylesheet editor that’ll appear in your dashboard, under Appearance > Edit CSS.

As alternatives, you could either install a standalone custom CSS plugin, or create a child theme.

/* =Menu
----------------------------------------------- */

#access {
	border: 3px double #eee;
	border-width: 3px 0;
	clear: both;
	display: block;
	float: left;
	margin: 1.615em auto;
	min-height: 43px;
	position: relative;
	width: 100%;
}
#access ul {
	clear: left;
	float: right;
	list-style: none;
	font-size: 14px;
	margin: 0;
	padding-left: 0;
	position: relative;
		right: 50%;
	text-align: center;
}
#access li {
	display: block;
	float: left;
	position: relative;
	left: 50%;
}
#access a {
	border-radius: 5px;
	color: #000;
	display: block;
	line-height: 21px;
	margin: 6px 10px;
	padding: 5px 10px;
	text-decoration: none;
}
#access ul ul {
	clear: none;
	background: #000;
	-moz-box-shadow: 0 3px 3px rgba(0,0,0,0.2);
	-webkit-box-shadow: 0 3px 3px rgba(0,0,0,0.2);
	box-shadow: 0 3px 3px rgba(0,0,0,0.2);
	display: none;
	float: none;
	margin: 31px 0 0;
	padding: 6px 0;
	position: absolute;
		top: 0; /* 31 + border-height*/
		right: auto;
		left: 10px;
	z-index: 99999;
	width: 200px;
}
#access ul ul ul {
	float: left;
	margin: 0;
	position: absolute;
	left: 200px;
	right: auto;
	top: -6px;
}
#access ul ul a {
	border: 1px solid #222;
	border-width: 1px 0;
	color: #ccc;
	font-size: 13px;
	margin: 0 0 -1px;
	padding: 5px 10px;
	width: 180px;
	height: auto;
}
#access ul ul li {
	float: none;
	left: auto;
	text-align: left;
}
#access li.current_page_item a,
#access li.current-menu-item a {
	background: #eee;
	color: #777;
}
#access li.current_page_item ul a,
#access li.current-menu-item ul a,
#access ul ul li.current_page_item a,
#access ul ul li.current-menu-item a {
	background: transparent;
	color: #ccc;
}
#page #access li:hover > a {
	background: #000;
	color: #fff;
}
#access ul ul :hover > a {
}
#access ul ul a:hover {
}
#access ul li:hover > ul {
	display: block;
}

wiefie – this thread is about Forever, not Twenty Fourteen. Although your tutorial isn’t in English, from what I gather it seems to suggest editing style.css. Editing the theme’s stylesheet directly is not recommended as you will lose all your changes when the theme is updated. Recommended ways of modifying CSS in a theme are listed above.