Weird mesh color?

so i made a low poly model of a gun in blender, and imported into roblox studio as .fbx
i tried to set all the colors to black, but one stupid part on the magazine was like a kinda light greyish color even though i set it to black
heres what i mean:


in blender:

i have a feeling this has something to do with the lighting, since when i started the game i could see its black before the lighting loaded…

PLESE HELP

nvm guys i remodeled the magazine part and it works fine now but im still curious why its like that in the first place