Who says that leaves are green

[wordgobbler]

Who says that leaves are green
Or sky is blue? --- You could say 'or that the sky is blue' 
Who says that days are always light
Or night is immanently dark? 
 
Who says what anything is really like? --- like what? maybe you could expand on that idea by asking, 'anything is really like it seems?' 

Who says I have to be like you?   
Who says you have to be like me?  i like this part 
For your green may be my blue
My light may not be light for you
 
… and my colors change as seasons go. --- this idea comes suddenly, maybe play with the idea of change before ending on this note.