You’ve done a fantastic job with both of these photographs. This is exactly what was asked of you.
Your first image uses the color palette of green, red and brown. The brown background acts as a neutral color that helps exaggerate the highly saturated red. I like how you’ve chosen to include little pieces of green in the image that help give the image more texture and detail. Without the green the image risks being too flat and lifeless. I think the image would have been overly simplified. The green helps complicate the image in a good way.
Your second image is also interesting and uses the color palette of yellow, brown and blue. An unusual color palette, but it works very well in this example. In this image you’ve chosen not to focus on an object. There is no 1 thing that your viewer’s eyes are drawn towards. This image is more about shape and color than it is about an identifiable primary object. It’s almost abstract in nature.
The only comment I have is for you to consider depth and layers in all of your photographs. It’s not always necessary to have a strong foreground, middle ground and background, but it’s always worth thinking about. If all of your objects are always located in the same are of depth, your images risk being seen as flat and 2 dimensional. Always think about that for your future projects.
Keep up the great work!