>> all_combinations([["red", "green"], ["large", "small"], ["denim", "silk"]]) { |*a| p a }
["red", "large", "denim"]
["red", "large", "silk"]
["red", "small", "denim"]
["red", "small", "silk"]
["green", "large", "denim"]
["green", "large", "silk"]
["green", "small", "denim"]
["green", "small", "silk"]