They don't need it. I have a lot of pacmans that I raised since they were babies. Some of them are 4.5 to 5 inches now. All I used for lighting was indirect light from my lizard tanks, and I also kept my room light on. I did however supplement them with some vitamins once in awhile. I did use a full spectrum light for a day or two to see what they would do, but they seem to want to jump out of their terrarium all the time.
If you have observed their behavior in a well set up terrarium you will notice that they burrow into the moss or other substrate you might use. They try to get away and cover themselves away from the light. Keeping out of sight and in a dim lit place also helps them get food because they are ambush predators. The only time that I see them come out into the open is at night, and boy do the males start croaking then.
Hope that helps with your lighting question. If you have anymore questions feel free to post again, I'd be happy to share my experiences about keeping pacmans.
Joel