diff --git a/public/css/theme0.css b/public/css/theme0.css
index e5cd6ba9..2a79695f 100644
--- a/public/css/theme0.css
+++ b/public/css/theme0.css
@@ -6304,18 +6304,30 @@ body {
 .footer a {
   color: #777777;
 }
-td.free {
+#shifts td.free {
+  border: 1px solid #777777;
   background-color: #f2dede;
 }
-atd.free:hover {
+a#shifts td.free:hover {
   background-color: #e4b9b9;
 }
-td.occupied {
+#shifts td.occupied {
+  border: 1px solid #777777;
   background-color: #dff0d8;
 }
-atd.occupied:hover {
+a#shifts td.occupied:hover {
   background-color: #c1e2b3;
 }
+#shifts td.collides {
+  border: 1px solid #777777;
+  background-color: #fcf8e3;
+}
+a#shifts td.collides:hover {
+  background-color: #f7ecb5;
+}
+#shifts td.own {
+  border: 1px solid #777777;
+}
 .space-top {
   margin-top: 15px;
 }
diff --git a/public/css/theme1.css b/public/css/theme1.css
index 75293613..e3a0e638 100644
--- a/public/css/theme1.css
+++ b/public/css/theme1.css
@@ -6327,18 +6327,30 @@ body {
 .footer a {
   color: #888888;
 }
-td.free {
+#shifts td.free {
+  border: 1px solid #888888;
   background-color: #d9534f;
 }
-atd.free:hover {
+a#shifts td.free:hover {
   background-color: #c9302c;
 }
-td.occupied {
+#shifts td.occupied {
+  border: 1px solid #888888;
   background-color: #5cb85c;
 }
-atd.occupied:hover {
+a#shifts td.occupied:hover {
   background-color: #449d44;
 }
+#shifts td.collides {
+  border: 1px solid #888888;
+  background-color: #f0ad4e;
+}
+a#shifts td.collides:hover {
+  background-color: #ec971f;
+}
+#shifts td.own {
+  border: 1px solid #888888;
+}
 .space-top {
   margin-top: 15px;
 }
diff --git a/themes/base.less b/themes/base.less
index cc7956bb..6832fb1a 100644
--- a/themes/base.less
+++ b/themes/base.less
@@ -10,12 +10,24 @@ body {
   color: @text-muted;
 }
 
-td.free {
-	.bg-danger();
-}
-
-td.occupied {
-	.bg-success();
+#shifts {
+  td {
+    &.free {
+      border: 1px solid @gray-light;
+      .bg-danger();
+    }
+    &.occupied {
+      border: 1px solid @gray-light;
+      .bg-success();
+    }
+    &.collides {
+      border: 1px solid @gray-light;
+      .bg-warning();
+    }
+    &.own {
+      border: 1px solid @gray-light;
+    }
+  }
 }
 
 .space-top {