make dialog background color configurable (#7320) (#7323)

diff --git a/AUTHORS b/AUTHORS
index 98bdf2b..1532b60 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -13,3 +13,4 @@
 Michael Beckler <mcbeckler@gmail.com>
 Alexandre Ardhuin <alexandre.ardhuin@gmail.com>
 Luke Freeman <luke@goposse.com>
+Vincent Le Quéméner <eu.lequem@gmail.com>