Select option still appears on the page even after PHP IF.. statement

I'm developing an Online Store with PHP, so at the productdetails.php which shows the details of products, I coded this:

if(!empty($pro_colors))
{
echo "
    <div class=''>
        <h4 class='' style='float:right'>&nbsp;:رنگ <span>*</span></h4>
        <select class='select-css'>      
        ";
        foreach($pro_colors as $colors)
        {
            echo "
                <option value='$colors'>$colors</option>
            ";                                          
        }
        echo "
        </select>
    </div></br>
";
}

So simply what it should do is that, if any color has been added to the product at db, it has to show the select option and if no color has been added to the db, the select option must not appear!

But when there is not data on db as color, it shows this:

print screen

However, my table looks like this:

print screen 2

So please tell me, how should I solve this problem ?!