Plz help me explain this sentence Greg Norman from the state of Queensland has long been a colorful fixture on the professional golf circuit. What does "a colorful fixture" mean?

The difference between "fluctuate" and "ebb and flow"? The sentence is: Because foreign exchange rates ebb and flow/ fluctuate, it is not always possible for exporters to know how much money they will receive from sales. The answer is fluctuate. Can you explain why?

Introduce myself I am a high school student who is living in a city in Vietnam. I became a member in the italki community because I want to improve my English so that I can study abroad next year. Studying university in Australia has always been my goal and I am sure that I would achieve it in the near future. One of the most special thing about me is that I can also speak Chinese (Cantonese and Mandarin) fluently as I have studied this language since I was 6. In my opinion, knowing these 2 foreign languages is kind of an advantage to me. I am the kind of person who is quite shy and I am not really good at making new friends. However, I am trying to be a friendly person now and I hope that I would meet lots of interesting people here and learn a lot of things from them. ^^