Use active class, on table. Using Bootstrap and printThis

I'm using Bootstrap as my framework.
To print parts of page i use "printThis" jquery plugin.

When i print a table, the active class wont show.
Active is filled row (cell).

How can i fix this?

HTML/php

if($day == "Mån"){
  $mark_monday = "active";
}

echo "<tr class='print_table_text ".$mark_monday."'>";

UPDATE CSS
I tried this, and only bold is in the print!?
I can see the "active" class added by bootstrap on webpage. But it´s not shown in the print.

.print_table_text {
  font-size: 10px;
}
.print_table_text.active {
  font-weight: bold;
  background-color: #000000;
}

PrintTHis

<script>
  $(document).ready(function () {
    $('#print_btn').click(function () {
        loadCSS: "css/printthis-print_all_usrs_time.css"
        $('#usr_name, #list_usr_time, #sum_worked_time, #break_page').printThis();
    });
});
</script>

UPDATE

I did remove the bootstrap class "active". And created an own class called grey. I used the style sheet to add background color grey. But the same problem accours. I can see the grey background in my browser, but not on the print.

$mark_monday = "bggrey";

.print_table_text.bggrey {
  font-weight: bold;
  background-color: #f5f5f5;
}

The bold attribute is on the print, but not the BG color.

Add this media query to your styles that will be applied for a print

@media print {
    td.active {
        background-color: #f5f5f5;
    }
}