Great work. Both of these images are very strong and accomplish precisely what was asked of you for this assignment.
The strongest components of each photograph, in my opinion, lies in your ability not only to control your color palette, but also to control the area around the edges of your photograph. Both images have a very noticeable concentration of their main subject without compromising the secondary elements within the frame, or the area around the edges of the photograph. Your ability organize doesn’t go unnoticed.
However, I do have a concern over the lighting in your first image. The image has a lot of potential, but appears flat because of the direction of the lighting. I would really like to you see you experiment with lighting more in your images. Even using small table lamps, candles, flashlights or other forms of movable lighting help you control both direction and intensity.
I would like you to watch the following lighting tutorial. Although the video is directed towards filmmakers, the ideas are exactly the same for photographers.
In your photograph I think that directional lighting could have helped add an interesting element to your composition.
Other than that… Wonderful work! I look forward to seeing your next assignment.