Phil, Both 216s and 235s in '52 were painted the same color, the dark-ish gray as discussed in this forum, called blue-gray in the Tech Article at this link: Jim Carter's Tech Article - Engine Paint Colors by Model Year
]. This article has the best compilation of colors I've seen, although I would be interested to know if others have a additional sources. EDIT: Tim beat me to it - looks like the same or similar list, in a different article. Cheers!
FWIW, the '59 235 would not have been Chevy orange from the factory... either gray (trucks) or blue (cars). I would favor the older 216/235 gray, FWIW.
If you are after the '52 look, consider a '53 or earlier valve cover, with the two central hold down studs. Easy swap using the earlier-style studs to replace two of the later engine rocker assembly hold-down bolts, as you probably know.