Accoding to Ugo Pericoli's Armies at Waterloo rank distinctions were also on the shako in 1815.
Colonel and Lieutenant-Colonel: two gold bands, top one 35mm, lower one 15mm, white plume
Major: top gold band 35mm, lower silver band 15mm, plume white tipped red
Chef de Battalion one gold band 35mm red plume
Captain one gold band 30mm (red plume for grenadiers, yellow or occasionally green for voltiguers, presumably appropriate pom-pom for centre companies)
Lieutenant one gold band 25mm
2nd Lieutenant one gold band 20mm
He shows a Legere officer with a silver instead of gold band.