Index: wp-admin/css/common.css
===================================================================
--- wp-admin/css/common.css	(revision 43972)
+++ wp-admin/css/common.css	(working copy)
@@ -2452,7 +2452,7 @@
 	font-weight: 400;
 	font-style: normal;
 	vertical-align: top;
-	transition: color .1s ease-in 0;
+	transition: color .1s ease-in 0s;
 	text-align: center;
 	color: #ffb900;
 }
Index: wp-admin/css/themes.css
===================================================================
--- wp-admin/css/themes.css	(revision 43972)
+++ wp-admin/css/themes.css	(working copy)
@@ -1181,7 +1181,7 @@
 	display: inline-block;
 	line-height: 1;
 	text-align: center;
-	transition: background-color .1s ease-in 0;
+	transition: background-color .1s ease-in 0s;
 }
 
 .background-position-control .background-position-center-icon {
Index: wp-includes/css/dashicons.css
===================================================================
--- wp-includes/css/dashicons.css	(revision 43972)
+++ wp-includes/css/dashicons.css	(working copy)
@@ -25,7 +25,7 @@
 	font-style: normal;
 	vertical-align: top;
 	text-align: center;
-	transition: color .1s ease-in 0;
+	transition: color .1s ease-in 0s;
 	-webkit-font-smoothing: antialiased;
 	-moz-osx-font-smoothing: grayscale;
 }