Makes the hint text darker for lower rows.

ui/keyboard/resources/elements/kb-row.html

Index: ui/keyboard/resources/elements/kb-row.html
diff --git a/ui/keyboard/resources/elements/kb-row.html b/ui/keyboard/resources/elements/kb-row.html
index d601c8e00dc7eeab124cbdf71fdc3df22c8b07e8..4cce396287350b691f0e4ff96f906c6671eab230 100644
--- a/ui/keyboard/resources/elements/kb-row.html
+++ b/ui/keyboard/resources/elements/kb-row.html
@@ -55,6 +55,18 @@
       border-bottom-color: #393939;
       border-top-color: #717171;
     }
+
+    :host:nth-child(2) ::part(hint) {
+      color: #2C2C2C;
+    }
+
+    :host:nth-child(3) ::part(hint) {
+      color: #272727;
+    }
+
+    :host:nth-child(4) ::part(hint) {
+      color: #232323;
+    }
     </style>
     <content select="*"></content>
   </template>