A neutral cardigan refers to a sweater that is not flashy or vibrant in color, but rather subtle and plain. It is usually a versatile and easy-to-match piece of clothing. Full definition
Neutral tee + neutral cardigan + jeans + scarf is my go - to outfit though! (truncationblog.com)
For work, I normally keep my wardrobe more traditional and wear a lot of neutral cardigans / jackets over a colorful top. (somethinggoldsomethingblue.com)