What I expected to happen was:

The tooltip of the structure blocks should be white and the border lines of the structure area should be red, green, blue and white. Also, if I enable "Show invisible blocks", air blocks should be blue and structure voids should be red.

What actually happened was:

The tooltip of the structure blocks is in a black or gray-ish color. The border lines, as well as the air blocks and structure voids if I enable "Show invisible blocks" are black.

Steps to reproduce:

• Place a structure block, set it to Save mode, and set the structure name.
• Create a random structure containing some air blocks and some structure voids.
• Select that structure using the structure block.
• Activate "Show invisible blocks" in the interface of the structure block.
• Et voilà – everything is black.

Attachments:

• black_structure_block_tooltip.png – Tooltip of a Save structure block which is in a gray-ish color and not really well readable
• black_structure_void.png – A test structure with "Show invisible blocks" enabled, focusing on a structure void

About this report:

I searched for other reports about this, but couldn't find any. I'm really sorry if I missed one. Might relate to lava being blood.