Refactoring for theme

src/ui/ButtonNavigator.js

@@ -27,9 +27,12 @@ var css = csjs`
   .jumpButton {
     ${styles.button}
   }
-  .navigator:hover {
+  .navigator {
     color: ${styles.colors.black}
   }
+  .navigator:hover {
+    color: ${styles.colors.orange}
+  }
 `
 
 function ButtonNavigator (_parent, _traceManager) {

src/ui/TxBrowser.js

@@ -36,9 +36,10 @@ var css = csjs`
   }
   .txbutton {
     ${styles.button}
+    color: ${styles.colors.black};
   }
   .txbutton:hover {
-    color: ${styles.colors.black};
+    color: ${styles.colors.orange};
   }
 `
 function TxBrowser (_parent) {