I used Glowstone Lamps instead.

*It's finished. Tazz has laid out Redstone blocks beneath the railways (which do not interfere with the power rails), then put the Glowstone Lamps on every side of the Redstone. As a decorative choice, he then covers the sides that stick out at the top with wood, making it all underwater. The railways are still lit, it's just much less obtrusive and fire-based now.*