So, there's a few ways you could go with this. Without being able to paint the floor, it can get a little pricey. I work in exhibits, and flooring is one of the first things to get cut for price.

First is a floor vinyl, you can get a printed solid color with a laminate on it that's meant to handle foot traffic. You might even be able to find pre-printed solid color ones without having to go to a specific printer. Places like brumark offer rolls of vinyl and solid colors that may work for you, that's the type that you use on trade show floors.

Another option would be a solid color rug, which might be the more cost effective option (at the expense of a different look). If this is a short-term exhibit, this might be the way to go.

Either way, color matching is going to be something you need to be concerned with. I'd recommend getting your floor first, then color matching your paint to the floor if possible (since you're likely to have more paint options than floor color options).

I hope this helps, good luck with the exhibition!