The word "decolorizing" refers to the process of removing or reducing the color of something. The antonyms or opposite words for decolorizing can be "coloring," "tinting," "pigmenting," and "dyeing." These words have a positive connotation as they add color to something. Other antonyms for decolorizing are "vivid," "lively," "bright," and "colorful." These words refer to something that is full of color or has a vibrant hue that catches the eye. The opposite of decolorizing is often used in art, fashion, and design to create a bright and appealing aesthetic.