When you double-click a Layered texture in the Scene browser, its properties display in the Properties window. These properties are mostly the same as those for standard single-layered textures, except for the BackGroundColor property.
Layered textures have a BackGroundColor property, which is set to black by default. When you have only one texture in a Layered texture and it involves transparency, you can choose a background color using this property.
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