Interesting note, I tried creating the TurretBase mesh manually (I.e. creating a body, then adding a collision shape) instead of using the Mesh contextual menu shortcut.
Worked… except, when the grid map was loaded, the TurretBase did not inherit the color I set (pale red, like Bram).
I went back and used the shortcut method, and then the color was recognized from this newly created asset.
Not sure if there is some other setting I would need to check/use if creating those manually?