So the activation page (for a multisite network) can be a bit difficult to style for a full-width site that has a background on the body and a background on the #content-sidebar-wrap. Since this section is not part of Genesis (or any theme/framework for that matter) and is part of WordPress (thus no real hooks within the page), you need to add a body class to be able to target style.

[php]
add_action( 'activate_header' , 'wps_add_activate_class' );
/*
* Call body_class filter on activate_header action hook that only appears on wp-activate.php
* @author Travis Smith
*/
function wps_add_activate_class() {
add_filter( 'body_class' , 'wps_activate_class' );
}

/*
* Add specific CSS class by filter
* @author Travis Smith
*/
function wps_activate_class( $classes ) {

// add 'class-name' to the $classes array
$classes[] = 'activation-page';

// return the $classes array
return $classes;
}[/php]

In a previous post I discussed how to create a child theme admin page, and talked about a few of the new features of Genesis 1.8, . However, one thing I didn't discuss in the creation of the new admin pages is setting a custom screen icon.

While this may or may not make Genesis core, it is a simple addition. So in your __construct() method with $page_ops, enter a screen icon of 'custom'.
[php highlight="22,23,24"]
/**
* Create an admin menu item and settings page.
*
* @since 1.0.0
*/
function __construct() {

// Specify a unique page ID.
$page_id = 'child';

// Set it as a child to genesis, and define the menu and page titles
$menu_ops = array(
'submenu' => array(
'parent_slug' => 'genesis',
'page_title' => 'Genesis - WPS Starter Settings',
'menu_title' => 'WPS Starter Settings',
'capability' => 'manage_options',
)
);

// Set up page options. These are optional, so only uncomment if you want to change the defaults
$page_ops = array(
'screen_icon' => 'custom', // see $this->screen_icon() below
);

// Give it a unique settings field.
// You'll access them from genesis_get_option( 'option_name', CHILD_SETTINGS_FIELD );
$settings_field = CHILD_SETTINGS_FIELD;

// Set the default values
$default_settings = array(
'phone' => '',
'address' => '',
);

// Create the Admin Page
$this->create( $page_id, $menu_ops, $page_ops, $settings_field, $default_settings );

// Initialize the Sanitization Filter
add_action( 'genesis_settings_sanitizer_init', array( $this, 'sanitization_filters' ) );
}
[/php]

Next you will need a method to output the necessary CSS to display your icon.
[php highlight="42,43"]
/**
* Create an admin menu item and settings page.
*
* @since 1.0.0
*/
function __construct() {

// Specify a unique page ID.
$page_id = 'child';

// Set it as a child to genesis, and define the menu and page titles
$menu_ops = array(
'submenu' => array(
'parent_slug' => 'genesis',
'page_title' => 'Genesis - WPS Starter Settings',
'menu_title' => 'WPS Starter Settings',
'capability' => 'manage_options',
)
);

// Set up page options. These are optional, so only uncomment if you want to change the defaults
$page_ops = array(
'screen_icon' => 'custom', // see $this->screen_icon() below
);

// Give it a unique settings field.
// You'll access them from genesis_get_option( 'option_name', CHILD_SETTINGS_FIELD );
$settings_field = CHILD_SETTINGS_FIELD;

// Set the default values
$default_settings = array(
'phone' => '',
'address' => '',
);

// Create the Admin Page
$this->create( $page_id, $menu_ops, $page_ops, $settings_field, $default_settings );

// Initialize the Sanitization Filter
add_action( 'genesis_settings_sanitizer_init', array( $this, 'sanitization_filters' ) );

// Add custom screen icon
add_action( 'admin_head' , array( $this, 'screen_icon' ) );
}
[/php]

Now you will need to create the method within the class extension.
[php]

/**
* Custom Admin screen icon
*
* See /lib/classes/sanitization.php for all available filters.
*
* @since 1.0.0
*/
public function screen_icon() { ?>
<style>
#icon-custom { background-image: url('<?php echo WPS_ADMIN_IMAGES . '/staff_32x32.png'; ?>'); background-repeat: no-repeat; }
</style>
<?php
}
[/php]