Change colour of menu and size

You’ll either need to edit the stylesheet for the theme, create a child theme with some custom styles, or use a custom CSS plugin – I’ll let you decide (let me know if you have questions about any of those options).

Looking through the stylesheet and playing a little with it on my computer, if you change

#access div {
    margin: 5%;
}

(Line 82 of style.css) to

#access div {
    margin: 0 5%;
}

you should end up with a thinner navigation bar.

To change the color you’re going to want to change the background properties of (Line 550 in style.css)

#access {
	background: #222; /* Show a solid color for older browsers */
	background: -moz-linear-gradient(#252525, #0a0a0a);
	background: -o-linear-gradient(#252525, #0a0a0a);
	background: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#252525), to(#0a0a0a)); /* older webkit syntax */
	background: -webkit-linear-gradient(#252525, #0a0a0a);
	-webkit-box-shadow: rgba(0, 0, 0, 0.4) 0px 1px 2px;
	-moz-box-shadow: rgba(0, 0, 0, 0.4) 0px 1px 2px;
	box-shadow: rgba(0, 0, 0, 0.4) 0px 1px 2px;
	clear: both;
	display: block;
	float: left;
	margin: 0 auto 6px;
	width: 100%;
}

If you just want a solid background you can keep the first background and remove the rest, then change the color (#222) to whatever you’d like it to be. If you want something more elaborate let me know and I’ll see what I can do.

Honestly I’m not sure of the best way to center the menu in the middle of the page, but changing the color is something I can help with.

If you just want a solid white background you need to replace the 5 background lines in #access (see above – style.css line 550) with one line background: #FFF (#FFF is plain white – if you want other colors I recommend checking out a tool like this). You’ll probably also want to add a line with color: #000 so the text will show up (#000 is plain black, you can replace it with whatever color you want).

If you want to maintain the gradient effect that is currently being used you’ll want to replace the #252525 and #0a0a0a in the various background lines with two different colors.