Edit the template unread_post_count.css:
Change:
To:
Change:
Code:
.postItemCount
{
background: @primaryDark;
padding: 2px 4px;
text-align: center;
font-weight: bold;
border-radius: 2px;
text-shadow: none;
margin-left: 2px;
}
To:
Code:
.postItemCount
{
background: @primaryDark;
padding: 2px 4px;
text-align: center;
font-weight: bold;
border-radius: 2px;
text-shadow: none;
color: white;
margin-left: 2px;
}