Ok… this may or may not be a simple question but here goes…

I have a multi-page document that contains two main colors throughout – one is Dark Blue and the other is Light Blue. I'm using both these colors as either solid or together as gradients. What I need to do is change the color theme for an alternate document with Dark Brown and Light Brown. The way I would make this change globally would be to delete dark blue and replace with dark brown and do the same for the other color. Work just fine, BUT what if, I just wanted to swap the colors without having to delete the actual original color swatch (dark blue)? I know I can make a dup of the swatch before deleting and, rename the original swatch name but doesn't seem like the best solution, unless it's the only solution. 

Anybody have idea's?

Thanks!

~Erick