Background color changed for microsoft button in social auth login/register

lms/static/sass/partials/base/_variables.scss

@@ -201,7 +201,7 @@ $twitter-blue: #55ACEE;
 $facebook-blue: #3B5998;
 $linkedin-blue: #0077B5;
 $google-red: #D73924;
-$microsoft-blue: #00BCF2;
+$microsoft-black: #000000;
 
 // shadows
 $shadow: rgba(0,0,0,0.2) !default;

lms/static/sass/views/_login-register.scss

@@ -509,16 +509,16 @@
         }
 
         &.button-oa2-azuread-oauth2 {
-            color: darken($microsoft-blue, 20%);
+            color: darken($microsoft-black, 20%);
 
             .icon {
-                background: $microsoft-blue;
+                background: $microsoft-black;
             }
 
             &:hover,
             &:focus {
-                background-color: $microsoft-blue;
-                border: 1px solid $microsoft-blue;
+                background-color: $microsoft-black;
+                border: 1px solid $microsoft-black;
                 color: $white;
             }
         }