A: That depends on the type of extensions and the fibers contained in them. If the extensions are made from natural human hair, you may be able to lighten them, provided they have not been excessively processed
prior to being incorporated into extension wefts.
Extensions made with synthetic fibers generally cannot be lightened or colored successfully. Even those made from animal fibers (which are generally yak hair) may or may not be
successfully and safely lightened. The quality of the extensions (and of the hair used to make the extensions) often parallel the level of adaptability which the extensions offer.
High-end extensions, such as are made from virgin human hair, can often be treated the way you would any hair, while the least expensive extensions are seldom useful except in the
state in which they come.
That being said, most extension lines offer such a varied range of colors that you can find the color you wish to use and would not need to lighten the extensions at all.