Slight tweaks to the skyroot plank texture

In my opinion, the stripped skyroot log + beam are wonderful blocks, but I find the plank texture to be a bit too harsh. My two potential suggestions would be:

1) Softening the dark parts of the texture (the grooves between the planks) You can see how less harsh grooves look on the blighted planks, compared to the skyroot ones

2) Brightening the color of the planks themselves, to be a bit closer to the color of the stripped log variant