Need help w/Yellow Brick Road, pretty please?

Over the years, there have been posts from people on the forum involved in a Wizard of Oz type outdoor event, but I can't find the thread. I'm face painting again this year @ a combo Haunted House/Enchanted Forest for older/younger folks. My husband & I enjoyed putting on haunted houses for charity when we lived in MA. This year, both of us are helping parents & teachers do this to help their kids take a trip to Wash. DC. The theme will be Wizard of Oz (75th anniversary of the film) Walter is designing some of it & participating in it. I'm not only working w/my team to do all the faces in the haunted house & paint outside during the 2 day event, but I'm designing & painting Munchkin land. My question is: Do any of you have an idea about how to paint a yellow brick road that can be walked on by hundreds over a 2 day period & then washed off w/a pressure washer? The school surface that we'll be painting is concrete. We already considered:
1- chalk...would rub off
2- duct tape...wouldn't stay & would be a safety hazard
3- Latex paint...one parent is testing it. MAY be able to remove from concrete after.

It's actually the wide, outside breezeway type walkway around the side of a school building. Any help would be greatly appreciated, both w/the pesky yellow brick road & scary faces on the Oz theme. We're going to "Zombify" Dorothy! TIA

Have you tried children's finger paint? It would dry fairly quickly, and wash off easily. I would mix up 3 or 4 different shades of yellow, and use large sponges cut into brick-sized shapes and sponge them on.
I have never tried this.
I just know that you can purchase finger paint by the gallon, and it is easy to wash off.

xoxo

Lisa, We never even thought of this.GREAT idea. We'll try it out ASAP. TY!!!!!!

Here is one of the links, Pat.

http://www.facepaintforum.com/t10943-photo-update-which-witch-is-which?highlight=which+witch+is+which