When you think of fire, you think of red. Not always true. Depending on the oxygen levels, fire changes colour. If a fire is yellow, then there isn't  much oxygen, but on the other hand, when fire is blue, the oxygen levels will be high. Another fun fact about fire is, fire can be GOOD for nature! You've probably heard of that big forest fire or some animal killed on bonfire night, but, suprisingly, many ecosystems benefit from periodic fires because they clear out dead organic materials. This video will tell you how to light a fire with flint and steel.