How do I replace font colors across the whole document?

So I know how to change a certain font across the whole document.

I can replace let's say, Times New Roman with Arial throughout the whole document.

However, what if I want to replace a font color?

For example, I want to change the black 0,0,0,0 with black 40,30,30,100 across the whole document, instead of searching one by one and replacing the existing color.

I'm using CS5 on PC