The Otto Manuscripts book by Guy Dempsey, Jr, shows the Grande Armee in 1807, with 3 Italian regiments in the VIII corps under Marshal Mortier.
Gen'l Dupas: 4th French light; 15th and 58th French line; Paris Guard!; and Wurzburg regiment.
Gen'l Loison: 1st and 2nd Italian light; 1st Italian line; Poles; Saxons; Wurttembergers.
Gen'l Dombrowski: 2 Polish infantry regiments; 2 Polish cavalry regiments.
Gen'l Zajoncek: 2 Polish infantry, 2 Polish Cavalry.
Cavalry under Gen'l Dury: 2nd Dutch Cuirassiers; 2nd Dutch Hussars.
Very colorful bunch!
A grenadier of the 1st Italian line wears a bearskin with brass plate; scarlet side plume; scarlet cords "drooping" down across the plates; and side scarlet "flounders."
Read green for the coat, otherwise like French line – long habit with white turnbacks; white lapels edged scarlet; Red collar and cuffs edged white, cuff flap not shown. white vest and breeches with long black gaiters.
Voltigeur shown with shako with white metal "diamond" or lozenge on front. Dark green cords and flounders; odd dark green (not quite) ball pompom.
Green brush epaulettes with yellow crescent. cuff flaps scarlet edged white.
There is no illustration of a fusilier. A second Voltigeur I shown with bicorn, but otherwise same as above.
I do not believe the line varied from regiment to regiment until the went to the white uniform. At that time reds and greens helped identify them "on sight."
GdeP