What to wear at the office Xmas party?

During the last four years, we had Christmas Parties at the company with a dress code: evening dress! What I really loved since I could buy a new dress and style up etc....what's not very often during the year. But this time we celebrated on a boat going along the river Rhine and dress code was: Casual ;-(.

Surprisingly, a lot of my colleagues havn't took that casual to serious and were dressed up anyway. Great!
I was thinking the week before what to wear, because "casual" is for me: Jeans and Shirt and I definitely wouldn't go to a Christmas party in jeans and shirt. Never! So I thought, maybe a simple black dress, maybe a dark blue skirt and black silk blouse, leather pant and white long silk shirt?!

The last minute, I decided to go with a white blouse, red shorts, black tights and black wedge booties!

What do you think? Too casual or does it fit? The boots look a bit too casual for this outfit on the pics, right?! But they are not as clumsy as they look on the pic!

Love,
K.