Brewing stand arms appear far darker than they should

Relates to MC-262410.

The bug

The three arms of brewing stands appear much darker than one would expect, to the point of being even darker than they are in Java Edition.

How to reproduce

1. Place a brewing stand

2. Optional but recommended for clarity: fill all three slots

Expected results

The arms and bottles would not be shaded at all, and would appear just as bright as a flower, for example.

Actual results

They look very, very dark.