The tiny grains of sand are tan.
I tried to make it longer, but I didn't like how it sounded at first. I hope this is good enough. :)
A little helpful hint though: questions like these are actually quite easy. All you have to do is basically describe whatever you're being asked to, just think of some words that could "describe" the topic, for example; tan, tiny, smooth, etc can be describing words. It's super easy. ☺