The bug

The color used on maps for pale oak saplings is the same color used for regular oak saplings. This is inconsistent for other very differently colored saplings like the cherry sapling, which is pink on maps. One would expect the pale oak sapling to match the color of pale oak leaves.

A screenshot is attached.

How to reproduce

1. Run the following commands:

   /fill ~1 ~ ~1 ~10 ~ ~10 minecraft:pale_moss_block
   /fill ~1 ~1 ~1 ~10 ~1 ~10 minecraft:pale_oak_sapling

2. Obtain an empty map, and fill the map
   The saplings appear bright green, unlike the color of pale moss blocks or pale oak leaves