Oscar Williams was definitely in the 5th Alabama Infantry Regiment at Gettysburg. Most of his company originally were in the 6th Alabama, but joined the 5th Alabama on April 27, 1862, as Company K, at the time the regiment was re-enlisting and reorganizing.
I do have a gap in my record of color bearers after the death of George Nutting. Archibald Thompson was the color bearer (wounded at Chancellorsville) prior to George Nutting. Archibald was from the same company as Oscar Williams.