I'd never heard of Amaranth before, had to look it up, purpleheart. The brown is fairly typical in newly worked and will develop the familiar purple within a week or so.
I'm very curious to hear how this bridge sounds when it's done, I imagine very dark sounding transmitting little information between the strings and the body like metals do. Just a guess I've never come across a wooden bridge on an electric bass before, are there any others?
Very impressive work, that looks like a very difficult task but I won't be that impressed until I see those matching wooden machines 😛