Why did the Greeks colonize outside of Greece?

As far as i am aware that was Rome which wanted to colonise all land. And it wanted to do that because of the same reason as The British, The French, The Dutch, The Germans and all others who have ever colonised any land through out history - Money, Power, Slaves, wealth, Resources (Natural Resources metals, food etc) and of course Women. It must be understood that wealth and money are two different things.