make sure you are using the same color of granite to craft them.
I haven't dyed the wall pieces, but have dyed the pavers.
I crafted a bunch of pavers and dyed them with white natural dyes.
And I think I got confused to which paver I crafted.
Needless to say, that I was crafting them to raise the roof on the original castle. And even though they are the same hue ID, they all look different colors of white.
so if you are wanting them a specific color
make sure you use "dull copper" granite on every one you craft