Although I used this kit to bring my Savanna Beige seats back to original color, you can change the color completely. And it really isn't that much work, especially with the seats out.
Check this link out:
https://leathermagic.com/leather-dye-recoloringpainting/
I saw an episode of Wheeler Dealers where they changed banana yellow seats in an old BMW Z-1 (the one with sliding doors) to black using something similar. It can be done. Just throwing it out there for you.
Before:
After:
