patch 7.4.1552
Problem:    ":colorscheme" does not use 'packpath'.
Solution:   Also use in "start" and "opt" directories in 'packpath'.
diff --git a/src/vim.h b/src/vim.h
index ea3c498..becc26a 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2289,8 +2289,10 @@
 #endif
 
 /* Used for flags of do_in_path() */
-#define DIP_ALL	1	/* all matches, not just the first one */
-#define DIP_DIR	2	/* find directories instead of files. */
-#define DIP_ERR	4	/* give an error message when none found. */
+#define DIP_ALL	    0x01	/* all matches, not just the first one */
+#define DIP_DIR	    0x02	/* find directories instead of files. */
+#define DIP_ERR	    0x04	/* give an error message when none found. */
+#define DIP_START   0x08	/* also use "start" directory in 'packpath' */
+#define DIP_OPT	    0x10	/* also use "opt" directory in 'packpath' */
 
 #endif /* VIM__H */