For each color, I took a gallon-sized Ziploc bag, dumped 4 cups of rice, 2T of liquid watercolor, and 3T of rubbing alcohol in, then sealed it and massaged it around to coat the rice evenly. Once it was evenly coated, I dumped it out onto paper towels on my tarp and let it dry outside. I didn't check it for like an hour and they were 100% dry at that point. I'm sure that they were dry earlier. Here they are drying initially.
Close up of the purple
Warning-- if you have anywhere to go looking like a grown-up right afterwards, wear gloves. And long pants. And long sleeves. Maybe a HAZMAT suit? My hands afterwards (my legs/feet/arms/clothes were all speckled as well, but not nearly as badly-- those liquid watercolors are definitely messy!).
Then once they dried, I combined them in a single container.