In 1876 the regimental standards of cavalry regiments contained a modified form of the Arms of the United States on a blue field. The regimental standard of the 7th Cav was blue.
There were only 2 statememts that the regimental standard was yellow. Both came from soldiers (Godfrey and Siefert) with service during the era of blue standards and yellow standards. Though it seemed to me these sourses were good, they were not enough to make a definite assertion that the flag lost by the 7th Cavalry was yellow.
In my article, I suggested that the yellow flag might have been an "eagle standard." Eagle standards were once carried by American regiments as a national color in place of the Stars and Stripes. The regimental standard in those days was a flag with only a scoll bearing the regiments designation. The regimental standards evolved from the eagle standards. My suggestion met with no particular acclaim, and if I were writing today, I would add the possibility that the yellow flag was some sort of unofficial HQ flag.
In comparing the differences between the flag in the 1868 photo and the flag from the battlefield collection, I concluded that they were different flags. There were differences in the shape of the eagle's wing, the scroll work, and the stars. The field appeared lighter than the blue field of the battleield flag.
A sketch was made of the flag that turned up at Crow Agency, Mont in 1921. It appears to be yellow; it's swallow-tailed, has stars and a scoll, and "CUSTER" above the eagle's head. It is possible that men unaccustomed to seeing the regimental standard and seeing this or another yellow flag may have assumed that it was a regimental standard.
While I may waffle on the yellow flag, I see no reason to believe that the flag in the battlefield collection was present with the regiment at Custer's Last Stand. Furthermore there is every reason to believe that a regimental standard or some form of unofficial HQ standard was lost at Custer's courageous last stand.
Col Graham simply guessed that the flag was with the pack train because there was a flag in the battlefield collection. All the enlisted men Graham talked to told him that the flag was lost. He didn't remember what Godfrey told him regarding the fate of the standard, and he couldn't find his notes. I could find no original source which supported Graham's guess work. By the way, Graham was a giant in the field of Custer battle research and was completely honest his his discription of his thought process in reaching his conclusion. He was simply mistaken. Such things are apt to happen to people who think.
While men who remembered that a flag was lost may be mistaken, there is so far a total absence of men who remembered that the flag was furled, cased, and with the pack train.
In the 1960's when I served in the Army the distiction between colors and standards was clearly defined, but the terms seemed to be used indiscriminantly in the 1860s and 1870s