Bricks, Masonry, Asphalt and Concrete - Restoring historic brick

I am restoring a 1780's brick plantation house that had been abandoned for some 20 years before I moved here, and had received indifferent maintenance before that. We've been repointing the brick and repairing all the holes, etc, removing the concrete joints that were put in during the 1940's, and in general doing everything you would expect in a restoration. Now the house looks like a patchwork. Between the century-old paint that's come off during the restoration and the new lines of mortar, the exterior looks just like you'd expect--like it's been patched. I'm looking now for a solution (one I can afford) that will unify the color of the house. I can't use paint, or anything that will seal the bricks because of the moisture problems that an exterior seal will cause in an interior. We want some kind of non-sealing stain that we can apply ourselves, because we're on a pretty tight budget. Any ideas? Thanks so much in advance, because I'm about completely out of ideas

I would probably use a portland/sand slurry and just rub into the joints. A lot of work, but it is cheap and reasonably durable and will even out the mortar color.