Try this yet?
In global.css find:
.forum_off, .forum_offlock, .forum_offlink {
color: #666;
}
.forum_offlock i:before {
content: "\f023";
}
.subforum_minioff, .subforum_miniofflock, .subforum_miniofflink {
color: #666;
}
.subforum_miniofflock i:before {
content: "\f023";
}
Replace with:
.forum_off, .forum_offclose, .forum_offlink {
color: #666;
}
.forum_offclose i:before {
content: "\f023";
}
.subforum_minioff, .subforum_minioffclose, .subforum_miniofflink {
color: #666;
}
.subforum_minioffclose i:before {
content: "\f023";
}
In index find:
<dt><div class="forum_status forum_offlock"><i class="fa fafolder"></i></div></dt>
<dd>{$lang->forum_locked}</dd>
Replace with:
<dt><div class="forum_status forum_offclose"><i class="fa fafolder"></i></div></dt>
<dd>{$lang->forum_closed}</dd>
Replace thread_staus.css with:
.thread_status:before {
font-family: "FontAwesome";
font-size: 16px;
}
.thread_status.dot_folder:before {
color: #a0a0a0;
content: "\f075"
}
.thread_status.dot_hotfolder:before {
color: #a0a0a0;
content: "\f06d"
}
.thread_status.dot_hotclosefolder:before {
color: #a0a0a0;
content: "\f06d"
}
.thread_status.dot_closefolder:before {
color: #a0a0a0;
content: "\f023"
}
.thread_status.dot_newfolder:before {
color: #0066a2;
content: "\f15c"
}
.thread_status.dot_newhotfolder:before {
color: #0066a2;
content: "\f06d"
}
.thread_status.dot_newhotclosefolder:before {
color: #0066a2;
content: "\f06d"
}
.thread_status.dot_newclosefolder:before {
color: #0066a2;
content: "\f023"
}
.thread_status.folder:before {
color: #a0a0a0;
content: "\f075"
}
.thread_status.hotfolder:before {
color: #a0a0a0;
content: "\f06d"
}
.thread_status.hotclosefolder:before {
color: #a0a0a0;
content: "\f06d"
}
.thread_status.closefolder:before {
color: #a0a0a0;
content: "\f023"
}
.thread_status.newfolder:before {
color: #0066a2;
content: "\f075";
}
.thread_status.newhotfolder:before {
color: #0066a2;
content: "\f06d";
}
.thread_status.newhotclosefolder:before {
color: #0066a2;
content: "\f06d"
}
.thread_status.newclosefolder:before {
color: #0066a2;
content: "\f023"
}
* I did not have time to look further at the theme as my time is limited and I am currently on a mobile device, nor did I focus on any other areas of an 1810 theme to get it updated to 1819 but the previous instructions should get you started/going on solving the question you asked