Apply Patch suggested by @markrian

app/assets/stylesheets/components/avatar.scss

@@ -68,7 +68,7 @@ $avatar-sizes: (
 );
 
 $identicon-backgrounds: $identicon-red, $identicon-purple, $identicon-indigo, $identicon-blue, $identicon-teal,
-  $identicon-orange, $gray-darker;
+  $identicon-orange, $identicon-gray;
 
 %avatar-circle {
   float: left;
@@ -125,8 +125,8 @@ $identicon-backgrounds: $identicon-red, $identicon-purple, $identicon-indigo, $i
 .identicon {
   text-align: center;
   vertical-align: top;
-  color: $gray-700;
-  background-color: $gray-darker;
+  color: $identicon-text-color;
+  background-color: $identicon-gray;
 
   // Sizes
   @each $size, $size-config in $avatar-sizes {

app/assets/stylesheets/framework/variables.scss

@@ -629,12 +629,14 @@ $note-icon-gutter-width: 55px;
 /*
 * Identicon
 */
+$identicon-text-color: #525252 !default;
 $identicon-red: #ffebee !default;
 $identicon-purple: #f3e5f5 !default;
 $identicon-indigo: #e8eaf6 !default;
 $identicon-blue: #e3f2fd !default;
 $identicon-teal: #e0f2f1 !default;
 $identicon-orange: #fbe9e7 !default;
+$identicon-gray: #eee !default;
 
 /*
 * Calendar

app/assets/stylesheets/themes/_dark.scss

@@ -236,7 +236,3 @@ $line-removed-dark: $red-200;
   color: $gray-900;
   border-color: $gray-800;
 }
-
-.identicon {
-  color: $gray-10;
-}