patch 7.4.1552
Problem:    ":colorscheme" does not use 'packpath'.
Solution:   Also use in "start" and "opt" directories in 'packpath'.
diff --git a/src/main.c b/src/main.c
index 7bbf248..8c7d3d6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -628,9 +628,9 @@
     if (p_lpl)
     {
 # ifdef VMS	/* Somehow VMS doesn't handle the "**". */
-	source_runtime((char_u *)"plugin/*.vim", TRUE);
+	source_runtime((char_u *)"plugin/*.vim", DIP_ALL);
 # else
-	source_runtime((char_u *)"plugin/**/*.vim", TRUE);
+	source_runtime((char_u *)"plugin/**/*.vim", DIP_ALL);
 # endif
 	TIME_MSG("loading plugins");