It is one of the most colourful and entertaining events in the USA, isn’t it? Разделительный
Is it one of the most colourful and entertaining events in the USA? Общий
Is it one of the most colourful and entertaining events in the USA or in the UK? Альтернативный
What is one of the most colourful and entertaining events in the USA? Вопрос к подлежащему
What kind of event is it in the USA ? Специальный
Where is it one of the most colourful and entertaining events? Специальный