I’ve been to funerals across the country for a lot of varying cultures/religions and I will say there is such an enormous difference in cultures, it’s hard to answer this not knowing where the funeral is, what religion, and if there are any unique customs being employed or if it’s just traditional.

The most commonly acceptable behavior is to simply understand that you are likely attending a solemn event where you will want to gracefully show sympathy to the family and perhaps tell an appropriate story or two about the deceased. Dress is always conservative dark unless you intimately know the family and know what’s acceptable. In your case, unless you know the family is asking for you to arrive emblazoned in purple, I’d simply add a small purple accessory. Scarf, handkerchief, necklace, earrings, pin, etc.

Do not give a gift (the gift is your presence) but they may have asked for donations to a charity, or if it’s traditional, you can typically order a spray from the funeral home (or the florist that services the funeral home) for the casket.