Gram stain in all except: urine, stool, water culture, sputum?

Stain is a colored compound is used to develop a contrast between the specimen and the background. Contrast will not be developed in urine, stool , water and sputum.

The Stool and water sample culture does not require Gram Stain 

stool and water dont require any gram staining as the color will be obscured by the darkness of stool

water culture, or stool, or urine