The retailer decided to revamp the premium range after customers claimed its ivory colour was "not noticeable" on shelves.
Asda has introduced the new packaging on around a dozen lines in the last week and will roll it out across the rest of the 650-strong range by Christmas.
"Customers were telling us the range looked the same as everything else and didn't stand out enough so we decided to bring the brand to life with a rich purple colour because it really brings out the quality message we offer," said a spokeswoman.
The new packaging would encourage more shoppers to trade up, she added. "Some customers have never tried Extra Special before because they haven't really noticed it," she said. "Also, if customers are in a rush and the products just blend in with everything else, they are not as likely to buy them."
Despite the packaging, Extra Special had performed well this year, she said, citing strong sales uplifts from its ready meals, cooked meats and burgers.
Shore Capital analyst Clive Black said he was surprised at Asda's choice of colour. "The interesting thing here is Asda has completely gone against its traditional corporate green," he said. "I think the ivory packaging did a good job of offering a premium message because it looked elegant, but the revamp will make the lines far more noticeable."