All red and orange wouldn’t be exciting and stimulating so much as just plain hideous. You need a quieter, more neutral colour against which to display the red and orange. Brown works better for this than blue or green.
Diamonds02, where do you live? Who owns the casinos? I’m wondering if they are owned by American Indian tribes (as is the case in parts of the U.S.). Perhaps they are decorated in what they consider to be traditional tribal styles. Here’s a list of all the casinos in the U.S. It notes which are American Indian:
Most casinos I’ve seen on land are similar in this regard. I always assumed it was an intentional strategy with the objective of directing your attention to the brightly light tables and slot machines. And then the carpets are usually dark and elaborately patterned for the same reason as in any large interior space open to the public–dark patterns hide the stains better.
I think the casinos I saw on ships, both times we went on a cruise, did have windows.
This is what I was going to say. Everything in a casino is designed to draw your attention to the games. Another thing you’ll have trouble finding in a casino is a wall clock.