The lettering on SOU 1116 sure looks black to me. FWIW, I saw and photographed more of the 1960's era all-aluminum cars (4000 series cement covered hoppers, 6200 series 3 bay covered hoppers and Big Johns) with black lettering than with green lettering. While I did not see that many silversides coal gondolas, and those I saw were early on all with the red lettering, later as these cars aged and the aluminum car bodies darkened, it was common to see them in the late SOU era lettered in white.
-----------------------------------------From: "Jim King"
To: ModelingTheSouthern@SouthernRailway.groups.io, main@SouthernRailway.groups.io
Sent: Wednesday July 15 2020 3:08:05PM
Subject: [SouthernRailway] Silverside gon slide on ebay
Looks to have been repainted at Coster prior to this 1970 display (trucks sideframes also silver). Lettering is green. Were they repainted green when shopped from original vermilion? Recent discussion here indicates no rhyme/reason for vermillion or green but I suspect vermilion’s fading, especially under abuse from coal service, might have played a roll in that. Could it be that Claytor liked green more than vermillion and, as he rose to “power” over Brosnan, he started to influence colors like he did when converting boxcar-red cabooses to red?