In that context, I would say use the ultraviolet as an accent stripe, probably bounded by the white. If you have black stripes and one purple stripe on white, it creates an interesting variation.

A much more subtle option is the barely-there design seen on some sweaters. Imagine a black sweater with ultraviolet stars on it. In most light, people wouldn't notice the difference, but under the right light, they would pop right out. It doesn't even need blacklight, full-spectrum or sunlight will show things that incandescent or fluorescent won't.