I bought a Sugar Baby watermelon at the farmers market yesterday. I eagerly cut into it for dessert tonight, and it is not red but a whitish color, with a bit of pink around the seeds. I will notify the vender, and I took a picture of it. I googled "uses for unripe watermelon," but it is not looking hopeful, especially as most of those recipes assume a pinkish color at the least. It is not sweet and has a slight cucumber taste to it. (Apparently, watermelons and cucumbers are distant cousins.)
Any suggestions? If not, I will throw it behind the shed.