Index: wp-content/themes/twentyten/editor-blocks.css
===================================================================
--- wp-content/themes/twentyten/editor-blocks.css	(revision 53847)
+++ wp-content/themes/twentyten/editor-blocks.css	(working copy)
@@ -265,6 +265,10 @@
 	font-size: 1.5em;
 }
 
+.wp-block-pullquote .block-editor-rich-text__editable {
+    color: inherit;
+}
+
 .wp-block-pullquote .wp-block-pullquote__citation {
 	color: inherit;
 	font-size: inherit;