Solution found

Using Unity atlases

1. Locate the original image and disable Alpha Transparency.

2. Premultiply by Alpha. The original atlas works normally.

I'm using Unity atlases to package images in my project. They display correctly in Studio, but not in Unity itself. I switched to using TexturePacker to output NoesisEngine format resources to Unity, which is recognized correctly, but still displays incorrectly. I see that the Inventory example work...