Cool handiwork, but after over 30 years in the industrial health and safety profession I have to agree with those saying it would be a huge no-no here in the U.S. - for both practical and legal reasons.

To be clear, many of those rules are just bureaucratic wishful thinking, at best, but you'd still find yourself sideways with the gov'mint guys that carry clipboards during routine inspections and you'd be totally upside down with lawyers if someone accidentally mistook it for the real deal during an emergency. (I've known cases where someone standing within arms length of a safety shower that ran all the way across an industrial site to get to a water spigot in the lunch room! Panic makes people do, otherwise, unexpected things!)

Re-paint it (white with a green cross, like someone suggested) and keeping it at home to salvage your creative efforts.