Our colored powder is designed not to stain, but since we can't control how it is used after it leaves us, we recommend only wearing clothing that you wouldn't mind being stained. It is just colored cornstarch and most of it will just blow right off unless you got wet. We haven't had any of our hair, skin, or clothing stained and we haven't had any of our customers or 5K runners tell us about any staining, but it's better to be safe than sorry on our end.
Here's my first hand experience with our color getting wet. We just helped a local elementary school PTA celebrate winning an award with a color party. It rained about halfway through. The kids didn't want to stop so we kept the party going in the rain. We were soaking wet and covered with color, but those were the happiest kids you ever saw. They only wanted to use their school colors - green and yellow. Thought I'd add that since I included a group picture. As were were wrapping up the event, I looked down at my arms and wiped the pile of yellow and green powder off of my arm and saw a hint of blue on my skin. I thought I was going to have my first stain. We have helped with a participated in a lot of events, just not in the rain so it was good for me to experience this first hand. I didn't shower any differently than normal when I got home and stepped out of the shower with no stains whatsoever. Everything came out of my clothes and shoes after only 1 wash.