American rock band which eddie vedder once jokingly claimed was named after his great-grandmother

The answer is - Pearl Jam.

Eddie Vedder has jokingly claimed that the famous american band Pearl Jam is named after his great-grandmother. Pearl Jam is one of the most influential rock bands during the 1990's and 2000's, and over the years they have gained a world status and wide audience. They are one of the bands that promoted the grunge music, and are considered as one of the three most influential grunge bands alongside the likes of Nirvana and Alice in Chains.

silk

indigo  

rice

all the other answers are wrong