Here is a graphic of the US Army 1st Cavalry Division from roughly 1933. Included is its color-system for subunit insignias before that was de-authorized in 1934. They basically had different styles and colors for the bend and horse head for each major subunit.
Also update on the next videos:
The next video will be an April Fools video. Don't want to spoil too much but it's going to be quite different from anything else I've done, with commissioned art, and the Templin Institute is on board
The video after that will most likely be the French Javelot Division video (basically an atomic age combined arms cavalry division in the 50s). That video is likely going to be sponsored by Ground News in early/mid April.