We chose to use our school colors for the run. The ingredients were simply: water, food color and vinegar. The color was completely washable. We had no complaints about skin irritants or such.
For 900+ students we bought:
10 boxes of 1 oz food color
1 large jug of vinegar
10 spray bottles
The cost was under $50. If you have parents donate the items, it could be free for you!
We put 100 drops of food color in each bottle. This was approximately half of each food color bottle. We put a couple of ounces of vinegar in each bottle to bring the color out on the shirts. No need to measure. Then we filled the bottles with water.
Permission slips were sent home to allow students to be sprayed. We tied a ribbon around each child's wrist who had permission. This way the sprayers knew exactly who was allowed to be sprayed. The volunteers who were spraying were stationed around the running area. We explained to the students that they wouldn't be sprayed by each person and they weren't to stop in front of the sprayers. We didn't want the kids soaking wet. We also wanted to preserve the spray so that we could keep our budget down. Each group was given 30 minutes of running time. We split the school into 3 groups.
The parents that spoke to me had a lot of positive feedback. They loved that they didn't have to buy anything. They were thrilled that the students were having a great time, building memories and exercising! If you have any questions about how we ran this, stop on by my blog and email me.