The bug

1.18-pre5 fixed MC-148422, a texture dissonance in which the sides of stripped dark oak logs appeared too bright. However, the edges of their top faces still do not sufficiently match the color of the sides. Notably, the top texture has a much more grayish bark edge than the sides, which are the expected brown.

While testing this, I also discovered that spruce suffers from a similar issue, which should also receive attention in much the same way. (Even oak seems a bit off when compared to others like birch and jungle. It might be worth revisiting all 6 (8?) stripped logs and making sure every single one's top and side match each other as well as they can.)

For spruce and dark oak, Programmer Art's textures seem to match each other much better - such matching is what would be expected of the default textures.

Default in 1.18-pre5:

Programmer Art and pre-18w43a:

How to fix

Fixing this issue would entail retexturing the "inside/top/bottom" textures for dark oak logs, spruce logs and possibly oak logs such that the outer ring of would-be bark blends into the side textures of the block much more smoothly, rather than the current dissonance. Again, Programmer Art's stripped spruce and dark oak logs are a great example.

Again, going the extra mile and having a good look at all eight of the stripped log blocks currently in the game may be advisable in order to tidy up any inconsistencies that this ticket might have missed.