Discomaster
Terrarian
First one is simple: Pink Gemspark Blocks. Made by combining pink gel with glass at a work bench, uses the same lighting as the pink torch.
Second one is more ambitious: Blacklight Gemspark Blocks. Made by combining obsidian with glass at a work bench, the blocks themselves would look visible, although very faint, but providing a unique kind of light around it highlighting certain florescent colors. Imagine having some placed near granite and marble... the bright white of the marble and the bright speckles on the granite would be brighter than usual, without lighting up any darker colors. Perhaps it could also have a tinge of purple, similar to the glow of demon torches (hence why I recommend obsidian).
Second one is more ambitious: Blacklight Gemspark Blocks. Made by combining obsidian with glass at a work bench, the blocks themselves would look visible, although very faint, but providing a unique kind of light around it highlighting certain florescent colors. Imagine having some placed near granite and marble... the bright white of the marble and the bright speckles on the granite would be brighter than usual, without lighting up any darker colors. Perhaps it could also have a tinge of purple, similar to the glow of demon torches (hence why I recommend obsidian).