The Twenty Twelve theme, like most themes from its era, doesn’t have many visual customization options. So you’ll need to use custom CSS code to pull this one off.
Add the following in APPEARANCE => CUSTOMIZE => ADDITIONAL CSS:
.main-navigation li a {
color: #ff0000;
}
Note that when you add the above code, you’ll not see any effect on your site immediately. That’s because you currently have only one menu item which is the currently-displayed page (ie homepage)… and the current page needs a different code.
But you’ll see the effect when you add another menu item, or when you go to another page (outside the homepage).
To change the text color for the currently displayed page, add the following code as well:
.main-navigation li.current_page_item > a {
color: #ff9900;
}
In both cases, you’ll need to change the color as desired. You can use any named color (eg red, blue, cyan, etc)… or pick a HEX/RGB color from here: https://www.htmlcsscolor.com/
Good luck!
