I love the idea of colored light sources though I think it would be simpler to have the source be a single block that could just be a variation of the Redstone Lamp. Perhaps crafted with a Redstone Lamp and a Dye of various colors (instead of complicating it with placing colored glass "modifiers" around a light source.)
I like colored glass but I think it would be hard to implement colored light from colored glass. It might be possible to make colored light with a light source in a separate implementation but I think that colored glass and colored sand (I would love to see red deserts like the American Southwest) would be sufficient.
The Meaning of Life, the Universe, and Everything.
Awesome Idea I go with the 2nd way and I would change the you could fill water bottles with the respective color of the water in a cauldron and be able to put that into another 1 just like the way the water in them currently works (Just so you can destroy the cauldron without losing the dyed water)