Decide the color of the carpet dye. If your existing carpet is light colored, you can select from a wide range of colors. The trick is to choose a darker shade than the previous one. The resulting color of the carpet also depends on the previous shade. For example, if the current color is blue, dyeing with a red colored dye will give a purple color carpet and so on. You can also opt for the darker color carpet dye that complements the interior design, curtains, walls, and furniture of the room.