We are building a quonset hut 25wx30lx14tall to live in. since it is all nuts and bolts we are limited on types of insulation. We are leaning towards open cell insulation and since it will be exposed we want to try to hide it as much as possible. We saw a ceiling like this painted brown in a hunting store but it didn't do it for me, what color would be best? We have a skylight and lots of windows on the endwalls so light is not an issue. We are using high end finishes ie:granite counter tops, stainless appliances, etc. any ideas?

First, I don't believe exposed foam will meet fire code, and does not have any vapor barrier properties to speak of.
Closed cell has a higher R-value, is considered a vapor retarder (depending on the density), and finishes smoother than open cell, for applying a finish. There may be a fire resistant coating that would make this legal in your area.