Index: wp-content/themes/twentyfifteen/css/editor-blocks.css
===================================================================
--- wp-content/themes/twentyfifteen/css/editor-blocks.css	(revision 55900)
+++ wp-content/themes/twentyfifteen/css/editor-blocks.css	(working copy)
@@ -912,6 +912,25 @@
 	margin-bottom: 16px;
 }
 
+/* Search */
+
+.wp-block-search__button {
+	background-color: #333;
+	color: #fff;
+	font-family: "Noto Sans", sans-serif;
+	font-size: 14px;
+	font-weight: 700;
+	text-transform: uppercase;
+}
+
+.wp-block-search .wp-block-search__input {
+  border-radius: 0;
+  color: rgba(51, 51, 51, 0.7);
+  font-family: "Noto Sans", sans-serif;
+  font-size: 1em;
+  padding: 0.5em;
+}
+
 /*--------------------------------------------------------------
 7.0 Blocks - Colors
 --------------------------------------------------------------*/