Why aren't the stains like crystal violet and safranin washed away with water during simple staining?

Staining is a technique of microscopy which enhances the contrast of the microscopic image by the addition of chemicals called the stains. Simple staining is the process of staining a cell with one stain or dye. Simple stains provide a quick method of studying the cell shape, size and the arrangement in the given sample. The stain used is a basic, cationic dye which is added over the sample. A cation is a positively charged ion. The cell wall and the cytoplasm of the bacterial cells have a negative charge. So, basic stains like safranin and crystal violet get attracted to the negatively charged cells, bind to the cells and do not get washed away.

when it is at an intermediate population density