Hello Katarzyna,
If I am not wrong, you painted a graduate sapper of the Imperial Guard, but there are some mistakes to modify, while the painting in general is nice. I try to explain, following the uniform, from top to bottom
The grenade on the top of the headgear is gold, not white.
The cord is mixed red ang gold, as the tassels
The mixing of colours on the epaulettes was not so regular, the fringes were more mixed.
The rolled overcoat on the haversack has to be dark blue, not grey
The ribbon of the queue was black, not red.
The colour of the coat has to be more and more dark, not so clear
The rounded gold badge on the sleeves, above the axes, is to get away, it did not exist
The gold edging on the belts has to be removed, they were entirely white, with a visible stitching, as in all the Guard belts generally
I think it's all, I'm sorry to give you these bad notices
Best regards
MdM