TwentyTen- How to change color of 2 buttons only on nav bar

IF I understand your question right and I assuming you are using Twenty Ten default theme, try playing with clor in these in style.css

#access ul ul a {
background: #333;
line-height: 1em;
padding: 10px;
width: 160px;
height: auto;
}
#access li:hover > a,
#access ul ul :hover > a {
background: #333;
color: #fff;
}

each menu button has a unique css class/id which you can use in style.css to define the color.

which this css class/id is depends on your setup;
if you look into the html code in the browser, you should be able to find these classes/ids:
example:

<li id="menu-item-70" class="menu-item menu-item-type-post_type"><a href="https://yoursiteurl.com/grid/">Grid</a></li>

the style to use for this would be:
#menu-item-70 { background:red; }

if you like to get some more specific help, you could post a link to your site.

ok thanks to alchymyth, i got it to work. Now ive been playing with the css all day to do one more little thing, but i cant get it to work. Im trying to place a border around each button in the menu bar so that the buttons are more visible.

i put:

border: 2px;
border-color: #fff;

in quite a few places directly related to the nav bar, but none of them work. How do i get this thing to work correctly?

you could try to use this style:

#access .menu-header li,
div.menu li {
	float: left;
	position: relative;
}

maybe change it to:

#access .menu-header li,
div.menu li {
	float: left;
	position: relative;
border:2px solid #fff;
margin-left:-2px;
}

the margin-left prevents double thick lines between nav tabs.