In these photos, you can see gray transite asbestos cement boards that have been installed in hallways, stairwells, and have even been painted to blend in with the regular sheet-rock wall textures.

Asbestos cement board found in a hallway of a commercial building
Transite asbestos board found in a stairwell of a commercial building
Asbestos wall coverings that have been painted to match the sheet-rock wall textures