This assignment asked you to working within a limited color palette in your quest towards simplicity. You’ve done an excellent job of that.
Your image contains a split complementary color scheme. You’ve used primarily gradients of red, blue and green. A split complimentary color scheme uses 1 color on one side of the color wheel (in your case: red), and then it uses two colors on the opposite side of the color wheel that are adjacent to one another (in your case: blue and green).
This is slightly different than a standard complimentary color scheme, because you’ve used 3 colors in total. By incorporating the third color which is adjacent to the blue (i.e. green) you’ve softened the tension that is inherently created in the complimentary color scheme.
From a composition standpoint, the image is also very strong. You’ve used the branch as a leading line coming in from the upper-left corner of the frame. Similarly you’ve used strong lines cutting through your frame from right to left (i.e. the telephone wires).
This image makes me think of the contrasts between human and natural environments. In your foreground you have a beautiful flower. In your background you have the symmetry and greyness of something created by humans (i.e. electrical wires).