Choose a dye color that will restore the original color or is slightly darker than the original.
Remove all furniture from the room(s) and any drapery that falls within a few feet of the floor.
Vacuum the carpet thoroughly to get rid of dirt and grit, and use suction attachments at corners and baseboards.
Hire a professional carpet cleaner or rent a carpet shampooer from a local retailer and clean the carpet 24 hours before application of the dye.
Place painter's tape and drop cloths along walls and baseboards to protect those areas from the dye.
Follow the instructions the manufacturer has provided to mix the dye and fill a clean spray bottle with the dissolved dye.
To begin using the dye, start with the farthest corner from the entry. Spray the dye in a small patch, about 1 to 2 feet square, and use a scrub brush to work the dye into the carpet. Use a circular motion for best results. Apply the dye evenly and then move to the next area requiring dye. Move back and forth across the room's carpet to complete the dyeing process and allow easy access to the room's entry at all times.
Replace the furniture and drapery after the freshly dyed carpet has dried. Drying times will vary but 24 to 72 hours should be adequate for most climates and weather. Dye the carpet a deeper, darker color by applying a second coat of dye after the first one has dried.