Which food-spoiling microorganism has a visibly fluffy growth and is white, grey, or some other color?

This microorganism is the mold.

Explanation:

Mold is a collection of filamentous fungal species that thrive on organic matter. These molds have the ability to decompose organic matter and are food destroyers.

A very common type of mold in our daily lives is the bread mold. Like most molds, bread mold has a cotton look. Regarding the coloration, they can mainly assume greenish, bluish, reddish or whitish tones.

Some types of mold are harmful to human health, such as bread mold and other foods. This is because they spoil and rot the food. When eating a food (bread, fruit, vegetables, etc.) it is always important to check that it is not moldy. If so, the right thing is to throw the food in the trash.

i think the answer is strength