This poster by Kevin Cantrell is gorgeous! Hot-stamped into a special paper, it turns transparent when backlit or held up to natural light. The poster is made in the U.S., but the words are in Portuguese. They say: Let There Be Lights.
I know the words are from the creation story in the Bible, but I think this poster would be amazing as non-traditional holiday decor. Pretty enough that you could keep it displayed all year long.
A lovely gift for your scripture-loving parents.