Is a woman whose husband has died obligated to take off her white clothes and replace them with green ones after her waiting period ends, or is this an innovation?

The woman whose husband has died must observe 'iddah (waiting period) and mourning during this period. This includes staying in her home, refraining from adorning herself with jewelry, adornments, and kohl, and not wearing beautiful clothes. As for wearing white clothes during the 'iddah and replacing them with green after it, there is no শরعي (Shar'i) evidence for this.