<p>I got the achievement with the brown pearl, so your friend's theory is, well, wrong.<br>The wrong. I also used to collect all these pearls in my dp and I didn't have 100 brown pearls - 2 types were mixed.<br>The pearl colour can be clearly seen in my bp:<br><br><img alt="" src="https://i.imgur.com/wtDiqRv.jpg" style="height:768px; width:1366px"><br><br>So the answer to your question is - colour doesn't matter, just the quantity of all pearls, which has to reach 100.</p>