Hello Jim,
Your thinking about boots is true. Generally, boots were black in campaign and service wear, the boots in red, green and yellow marroquin leather were more delicate and used for parade and walking dress. However, in the period 1804-5, when we can locate the uniform of this man, officers wore often coloured boots and rich uniforms even at war, especially on the the great battles as Austerlitz for example (not in marching order).
I say also remember to remove the leaves and other ornements from the cartridge pouch, hussars officers have normally a little eagle, or nothing. Numbers, leaves and horns were generally used by Chasseurs officers. Although I have a photo of an original cartridge pouch used by an officer of 2nd Hussars with number and leaves, but this object was personal for that officer, it was not a generalized use.
Regards
MdM