Add blueberries, raspberries and yoghurt and then have it for breakfast.

I don't see that as appealing, but I could add it to other foods. I used to make refrigerator oatmeal, adding pureed fruits to oatmeal and chia seeds, mixing it in a jar or bowl and letting it sit in the fridge at least over night. I would use the yellow watermelon that way, the color and flavor would be camouflaged, and you'd get the health benefits.

Yeah, I'm not eating that with my mouth...

There are lots of different yellow watermelons, just like with red. Some are great, some bland. Some almost chartreuse, some almost orange. Also, even good varieties can have bad years, and so on. I usually try to grow some of each, and try different varieties each year. A plate full of red and yellow slices can be very appealing.

Yellow meated watermelon is just as sweet as the red here in Oklahoma.