The lines "A picture's worth a thousand words, But you can't see what those shades of gray keep covered" means that you can say a thousand words about the picture and what you think is going on in the picture, but you have no idea what it was actually like unless you were there, and saw it in color. the shades of gray keep covered all the things that you cant see in the picture, like how the people were acting and how they felt and everything.
Like when he is singing about being in Wolrd War II, for example. If it looks like they were scared to death, you have no idea how scared they actually were unless you were there with them and "saw it in color" so to speak.
The lines "A picture's worth a thousand words, But you can't see what those shades of gray keep covered" means that you can say a thousand words about the picture and what you think is going on in the picture, but you have no idea what it was actually like unless you were there, and saw it in color. the shades of gray keep covered all the things that you cant see in the picture, like how the people were acting and how they felt and everything. Like when he is singing about being in Wolrd War II, for example. If it looks like they were scared to death, you have no idea how scared they actually were unless you were there with them and "saw it in color" so to speak.