Differences between the built-in [colorbox](/home/sigal/.local/lib/python3.6/site-packages/sigal/themes/colorbox) theme in sigal and bgstack15 theme.
diff -Naur colorbox/static/css/style.css bgstack15/static/css/style.css
--- colorbox/static/css/style.css	2021-01-24 14:32:13.428676605 -0500
+++ bgstack15/static/css/style.css	2021-01-24 16:11:59.211313409 -0500
@@ -1,4 +1,4 @@
-body { background-color: white; }
+body { background-color: #e2e2e2; } /* modified bgstack15 2021-01-24 */
 /* Override a few styles from skeleton */
 h1 { font-size: 4.0rem; }
 h2 { font-size: 3.6rem; }
diff -Naur colorbox/templates/album.html bgstack15/templates/album.html
--- colorbox/templates/album.html	2021-01-24 14:32:13.437676429 -0500
+++ bgstack15/templates/album.html	2021-01-26 19:48:12.152651121 -0500
@@ -29,8 +29,9 @@
         <a href="{{ media.url }}" class="gallery" title="{{ media.title }}"
           {{ img_description(media) }}>
         {% endif %}
-          <img src="{{ media.thumbnail }}" alt="{{ media.url }}"
-              title="{{ media.title }}" /></a>
+          <img src="{{ media.thumbnail }}" alt="{{ media.url }}"{# bgstack15 added this if..media.title #}
+              title="{{ media.title }}" />{% if '.jpg' not in media.title or settings.edit_enabled %}<br>{% endif %}{% if '.jpg' not in media.title %}{{ media.title }}{% endif %}</a>{% if settings.edit_enabled %} <a style="font-size: 66%;" href="{{ settings.edit_cgi_script }}?index={{ album.index_url }}&image={{ media.url }}&id={{ settings.gallery_id }}">{{ settings.edit_string }}</a>{% endif %}
+     {% if media.description %}{{ media.description }}{% endif %}
       </div>
       {% endif %}
       {% if media.type == "video" %}
@@ -43,12 +44,13 @@
           {% endif %}
             {% if media.big %} data-big="{{ media.big_url }}"{% endif %}>
             <img src="{{ media.thumbnail }}" alt="{{ media.url }}"
-                title="{{ media.title }}" /></a>
+                title="{{ media.title }}" /></a>{% if ('.mp4' not in media.title and '.webm' not in media.title) or settings.edit_enabled %}<br>{% endif %}{% if ('.jpg' not in media.title and '.webm' not in media.title) %}{{ media.title }}{% endif %}</a>{% if settings.edit_enabled %} <a style="font-size: 66%;" href="{{ settings.edit_cgi_script }}?index={{ album.index_url }}&image={{ media.url }}&id={{ settings.gallery_id }}">{{ settings.edit_string }}</a>{% endif %}
+            {% if media.description %}{{ media.description }}{% endif %}
         </div>
         <!-- This contains the hidden content for the video -->
         <div style='display:none'>
           <div id="{{ mhash }}">
-            <video controls>
+            <video controls height="100%" width="100%">
             <source src='{{ media.url }}' type='{{ media.mime }}' />
             </video>
           </div>
diff -Naur colorbox/templates/album_list.html bgstack15/templates/album_list.html
--- colorbox/templates/album_list.html	2021-01-24 14:32:13.437676429 -0500
+++ bgstack15/templates/album_list.html	2021-01-26 11:07:33.304994900 -0500
@@ -13,7 +13,7 @@
         <a href="{{ alb.url }}">
           <img src="{{ alb.thumbnail }}" class="album_thumb"
               alt="{{ alb.title }}" title="{{ alb.title }}" /></a>
-        <span class="album_title">{{ alb.title }}</span>
+        <span class="album_title">{{ alb.title }}<p></span>
       </div>
     {% if loop.last or loop.index % nb_columns == 0 %}
     </div>
diff -Naur colorbox/templates/base.html bgstack15/templates/base.html
--- colorbox/templates/base.html	2021-01-24 14:32:13.437676429 -0500
+++ bgstack15/templates/base.html	2021-01-26 19:48:52.253246381 -0500
@@ -43,7 +43,7 @@
 
         {% if album.description %}
           <div id="description" class="row">
-            {{ album.description }}
+            {{ album.description }}{%endif%}{% if settings.edit_enabled %} <a style="font-size: 66%;" href="{{ settings.edit_cgi_script }}?index={{ album.index_url }}&image=folder&id={{ settings.gallery_id }}">{{ settings.edit_string }}</a>{% if album.description %}{% endif %}
           </div>
         {% endif %}
       </div>
Footer.html is from the default sigal theme.
diff -Naur colorbox/templates/footer.html bgstack15/templates/footer.html
--- colorbox/templates/footer.html	1969-12-31 19:00:00.000000000 -0500
+++ bgstack15/templates/footer.html	2021-01-24 16:12:46.323753022 -0500
@@ -0,0 +1,16 @@
+<footer>
+  <p>
+    {% if album.author %}
+      <span>&copy; {{ album.author }}</span>
+    {% endif %}
+    {# removed "generated by sigal" text from original footer.html bgstack15 #}
+    {% if 'sigal.plugins.feeds' in settings.plugins %}
+      {% if settings.rss_feed %}
+        <span><a href={{ settings.rss_feed.feed_url }}>RSS Feed</a></span>
+      {% endif %}
+      {% if settings.atom_feed %}
+        <span><a href={{ settings.atom_feed.feed_url }}>Atom Feed</a></span>
+      {% endif %}
+    {% endif %}
+  </p>
+</footer>
Links.html is from the default sigal theme.
diff -Naur colorbox/templates/links.html bgstack15/templates/links.html
--- colorbox/templates/links.html	1969-12-31 19:00:00.000000000 -0500
+++ bgstack15/templates/links.html	2021-01-26 20:24:11.346480465 -0500
@@ -0,0 +1,10 @@
+{% if settings.links or settings.edit_enabled %}
+<nav id="menu">
+  <ul>
+    {% if settings.links %}{% for title, link in settings.links %}
+    <li><a href="{{ link }}">{{ title }}</a></li>
+    {% endfor %}{% endif %}
+    <li><a href="{{ settings.toggle_link }}?id={{ settings.gallery_id }}">{% for value, text in settings.toggle_editing %}{% if settings.edit_enabled == value %}{{ text }}{% endif %}{% endfor %}</a>
+  </ul>
+</nav>
+{% endif %}
diff -Naur colorbox/templates/media.html bgstack15/templates/media.html
--- colorbox/templates/media.html	2021-01-24 14:32:13.438676357 -0500
+++ bgstack15/templates/media.html	2021-01-24 15:54:56.374587308 -0500
@@ -16,6 +16,7 @@
   <div class="thumbnail">
     {% if media.type == "image" %}
       <img src="{{ media.url }}" alt="{{ media.title }}" title="{{ media.title }}" />
+      <p>{{ media.title }}</p>
     {% endif %}
     {% if media.type == "video" %}
       <video controls>