An item is considered color fast if the dyes used in its construction do not bleed or run when exposed to water or cleaners. The basic test for colorfastness involves gently rubbing a clean, white cloth saturated with water or cleaning solution onto the item to check to see if any color bleeds or transfers. The color fastness of an item determines the manner in which you can clean and remove stains. While the test offers a simple way to check items for color fastness; clothing, upholstery and carpeting will need slightly different care and handling during the test.

Clothing

Find a hidden area of the clothing to spot test the cleaning solution to ensure color fastness. The inside collar of shirts or the interior part of pants waistbands generally make inconspicuous testing areas. S. C. Johnson, the maker of Shout stain remover, suggests also checking the garment label to help determine color fastness. If the instructions ask you to wash the item separately in cold or cool water, this might indicate that the item is not color fast. Consult garment labels or your local dry cleaning professional for specific information on how to clean and remove stains from materials that are not color fast.

Upholstery

Determine the color fastness of upholstery before cleaning it with any substance, including water, to avoid fading and color bleeding. Many upholstery manufacturers automatically include a color swatch of your fabric with your purchase so that you can use it for testing; if not, simply ask for one. If you need to color fast test your actual upholstered furniture, try testing the underside of a sofa cushion or another place where you won't notice any discoloration. The Michigan State University Extension recommends testing for colorfastness with a clean white rag or paper towel. If bleeding occurs, retest it using a slightly acidic cleaner. If the colors bleed when using the acidic cleaner, your only home cleaning choice involves spot cleaning it with a dry cleaning solvent. For safety reasons, they recommend that overall cleaning with the solvent be done by professionals.

Carpets and Rugs

Check the color fastness of carpet and rugs before applying any type of cleaners or spot treatments. Make sure you choose an inconspicuous area, such as a closet or hidden corner. If installing new carpet, you might want to ask for a remnant to use for color fastness testing. According to American Rug Laundry, older Kilims (flat tapestry-woven rugs) from Turkey or Persia are generally not color fast. Virtually all silk rugs made in Iran also contain dyes that bleed or run, as do many new rugs from the country. Make sure you check all of the colors in your rug; while some colors will potentially resist bleeding, others might not, which will leave your rug ruined and discolored. Talk to a professional rug or carpet cleaning company for advice on how to care for non-colorfast items.

Source:

Michigan State University Extension: Testing Upholstery Cleanability

Shout: On What Type of Clothing Can I use Shout Laundry Remover?

American Laundry: Oriental Rug and Carpet Care Tips

Resource:

Carpet Cleaning Tricks

Freshman Laundry Tips

Arm & Hammer: How Do I Test for Colorfastness?