Tennis shoe soles are typically made of rubber or a synthetic material in white or other colours such as grey, black or yellow. When a person refers to restoring "yellow" soles, this may refer to restoring yellow-coloured soles or soles with yellow discolouration from natural material ageing or heat damage. Whether you're trying to restore dirty yellow-coloured soles or soles with yellow discolouration, the methods to restore the soles are the same. You simply wash and scrub the soles gently to remove surface level dirt and debris and then use slightly more aggressive measures to deal with stains and discolouration.
Scrub the soles of your tennis shoes with a soft-bristled brush outside or over a dustbin or bucket to dislodge and remove as much dry debris as possible.
Wet the bottom and sides of the sole of the first tennis shoe. Wet a white, lint-free microfiber cloth. Apply enough mild detergent to the cloth to make it soapy.
Wash the bottom and sides of the sole of the first tennis shoe with the cloth. Scrub the surface as needed with a wet soft-bristled brush to remove any remaining debris.
Rinse the soap from the sole and then check the sole for remaining stains or discolouration.
Apply paste-style toothpaste to any stained areas that you find and then wait 30 minutes. Scrub the areas. Rinse and check the sole again.
Dampen a melamine resin foam eraser, if necessary. Rub the areas that you scrubbed to finish restoring the sole.
Dry the sole with a cloth. Set the tennis shoe aside.
Repeat the entire process with the second tennis shoe.
Rubbing your tennis shoe soles with a soft, white artist eraser can also remove some stains. If you're dealing with hard-to-remove yellow discolouration on the side of a white sole, apply liquid white shoe polish to cover the yellowing.
Reduce future yellow discolouration by never drying your tennis shoes in a dryer with heat or placing the shoes in direct sunlight to dry. Never use bleach or harsh chemicals to clean or restore your tennis shoes unless otherwise recommended by the manufacturer of the tennis shoes.