All trident textures are black
What I did before
I got lost, so I went back to bed with "/kill @e".
It was night, so I slept in a bed (red).
When I went to see the trap tower, a long time ago, the texture of the trident that hit the building was black.
*Please note that the translation may not be done correctly because this uses Google Translate.
The trident bounding box is inside of the planks, where the light level is 0, so its texture darkens accordingly. All entities in the game have always behaved this way. This is not a bug.