Illustrator tips

Is there anyone good on illustrator that can help save time. Lets say you have atwork with various colors and would like to select the entire page and then select any part that is green to…(any of your choice color)
this is to basically avoid having to go select each little piece one by one to then change its color.
Your tips will be greatly appreciated.

Thanks very much in advance.

(Topic is old so I will not be too precise)

In the top bar should be option to select similar by color.

Thanks, I appreciate it!