// If the old 'fl_link_color' hasn't been set
// Or if the new 'fl_visual_options' hasn't been set
// Then, add the defaults
if ((!get_option( 'fl_link_color' )) || (!get_option( 'fl_visual_options' ))) {
    global $options;
//Create an array to hold the defaults.
    $defaults = array();

    foreach ($options as $value) {
        //Similar to saving. Go through each value grabbing the key & value (item).
        foreach($value as $key => $item) {
            //Match the ids against the key.
            if(preg_match('/^id/i', $key)) {
                //replace the id so we can grab the correct numbered default value.
                $num = preg_replace('/^id(.*)/i', 'std$1', $key);
                //Make sure said value exists as it may not have a default value
                //Notice the use of $value as we want to grab the value from the
                //Previous loop, not this one.
                if(isset($value[$num])) {
                    //Store value in the defaults array using the field name as key
                    //And grabbing the value from the previous loop using the replaced
                    //ID as the key name.
                    $defaults[$item] = $value[$num];
                }
            }
        }

    }
    //Store new ones
    update_option( 'fl_visual_options', $defaults);
}