Painting a landscape

For this assignment we had to paint a landscape. In the painting we had to show depth by using different colours. So we had to use different kinds of green for the grass and different blues for the sky.
While painting I had a bit of red on my brush. It mixed with the blue of the sky. I started painting and there were some purple stripes in it. First I thought it was a problem, but later it looked good. It gives the sky a natural look. Normally a sky has also more than one colour.
I had a seven for it, which I think is fair. The landscape by itself is ok, but I’m not fully happy with the way I have painted the clouds. There had to be more white in it, but all in all I like the landscape.