I'm not sure why I seldom make this pretty, refreshing salad in the colder months, except that the 'winter' watermelon that's available (from where, Patagonia ? ) just isn't very sweet. Mid- March isn't exactly summer here, but I bought a container of cut-up melon today anyway so we could enjoy this salad with the first outdoor-grilled pork chops of the year.
At home we enjoy this as a side, but I made this into a popular entree salad at the club's restaurant by adding strips of cooked chicken breast. The pink shades were perfect for several pin-themed charity lunches supporting breast cancer research. The salad is very low fat/low calorie and low carb too, if you use a fat free and/or low sugar dressing. The original recipe used a homemade poppyseed dressing but I like it much better with a raspberry dressing. It adds to the visual appeal as well. I'm partial to Ken's Raspberry Walnut Vinaigrette low-sugar version or Panera's, but there are several others too.
As for the recipe, just use baby spinach or tear larger leaves in half. Add cut up ripe watermelon, fresh red raspberries, halved green grapes, slivered almonds, and whatever you decide to use for the dressing.