Understanding Color Critique

My best photo is either my monochromatic or my blue and yellow picture. I feel like the monochromatic picture is interesting to look at and has a nice composition. The green grass and green hand paint I think looks like it matches pretty well. The blue and yellow picture truly shows the two colors together and fun to look at. I also think this picture has nice shapes and textures. My worst photo is the red and cyan picture. It is not interesting to look out and has no texture. The apple is smooth and the cyan is also smooth. It is definitely my wort picture out of my whole project. I feel like I need to put more shapes and something that makes the picture pop out a little more.