These layout suggestion and layout re-do's were done as a part of Course 1, Lesson 8A, on Visual Weight. I invite you to be brave and participate by senidng me a layout. It is how I learned to grow in skills, with others giving me suggestions.
1. contrast - I can read your text okay and your photos pop, so the contrast is okay.
2. size - Your photos are large enough, just right.
3. color - the blue and purple do coordinate with the green of the foilage in the photos, but I'm not sure that they help bring the eye to the photos. I think that if you would use green elsewhere in your layout, it would help to bring the eye to the photos. You could either use a green frame instead of the purple or a green mat.
4. shape - I spy nice rounded corners!
5. texture - Not applicable.
6. isolation - Not applicable.
7. value - Not applicable.
8. balance - You do have a problem with balance. This is the biggest problem I see in most of your layouts. First, remember that a bottom heavy layout looks better. You did center the title nicely at the top, and technically it is balanced, but in actuality, it makes the layout a little top heavy. Do not hesitate to leave empty space at the top of your layout. Just slide the title down some on the page and you will see how much better such a small change will make!
Also, your photos are not grounded. (Yes, that's a tutorial I desparately need to write!) Your photos are just floating on the page. To ground them, put a mat under them that touches at least two sides of the page (in this case, horizontally). Try to remember the Rule of Thirds and make the mat either one-third of two-thirds the size of your page. Remember that bottom weighted is better, so put it more towards the bottom than the top to help weight it down. It does not have to go completely under all of the photos, but touching all of them in some small way is all that is needed.