How to tint/colorize a mega scan asset with Data Layers

In the Valley of the Ancient Demo, the dark world puts a grey theme on the light world campfire area to blend it with the rest of the dark world assets. When in editor all those assets still appear red-ish orange like the light world, rather than the grey seen in the dark world when playing in editor.

Does anyone know what is happening to make the mega scans appear grey without needing to go into each material to alter the albedo tint? Is it affiliated with the Data Layer system?