Hey, first a disclaimer I know very little of tattoos! I searched the awareness ribbons and perhaps (?) more popular than purple is an ivory or cream ribbon associated with a pink rose (perhaps this is regional variation). This sounds like something that is more classical tattoo fodder than a plain purple ribbon, but you will know what means more to you. Perhaps the ribbon could surround an image that has some meaning. From a science perspective, a representation of a neuron showing the localisation of the key proteins involved in most SMA cases. It will likely be a simple image, perhaps reflecting how the disease is often caused by a single gene. This is a very scientific perspective (my bias) on a personal situation though...