Although the support of subSilver2 is dropped since phpBB 3.2, the previous branch (phpBB 3.1) is now still supported. So, I report here some bugs in subSilver2 for phpBB 3.1.10...
Empty Profile fields : if the user define a value for Google+, Facebook, Skype, Twitter or Youtube, nothing is displayed in 'Viewing profile' (no button, no link or no value) after the mentions "Google+ :", 'AOL :'', "Facebook :", "Skype :", "Twitter :", "YouTube :".
Private Message colours: that feature simply doesn't work. You can see the legend text, but no colors (ucp_header). There is also no color at all in ucp_pm_viewfolder.html.
No category separator after a forum link: consider a category with subforums, then a forum-link and finally a regular forum without subforum. In proSilver, the index are displayed as "category separator / subforums" and below "Forum" separator and then the forum-link and the regular forum. In Subsilver2, however, the second separator doesn't displayed. If you modify the order (the regular forum above the forum-link), the second separator reappears. In fact, a <!-- IF forumrow.S_NO_CAT --> is missing in the template. To resolve that issue, open forumlist_body.html and replace that code
Code direction in print view is not defined as "ltr" : it's the same bug that I previously reported for proSilver (see phpBB3-15195). But because there is no bidi.css or print.css in subSilver2, the "direction: ltr" of .codecontent class should be defined inside the style tag in viewtopic_print.html and ucp_pm_viewmessage_print.html.