[JanMove]

I don't think that different countries have different regulations for the table's color. Here, in Switzerland, approximately 50% of the Clubs play with blue tables and 50% with green tables, while more than 80% of the Clubs use yellow balls. I prefer playing on blue tables in combination with yellow balls. This leads to the best optical contrast! My ranking for the combination of tables with balls is as follows:
1. blue table & yellow balls (best optical contrast)
2. green table & white balls
3. blue table & white balls
4. green table & yellow balls (worst optical contrast)

JanMove