The Greek that is translated as “countenance fell” (Revised Standard Version) or “became sad” is translated into Tase Naga as “his face was transformed” (source: Gam Sheng Sae) and in the Welsh Beibl Cymraeg Newydd Diwygiedig 2004 idiomatically as “his countenance clouded” (source: Iwan Rhys Jones in The Bible Translator 2003, p. 240ff. ).
See also countenance fallen / look sad and countenance fell.