Talk:Magic/@comment-71.214.60.49-20121024040241/@comment-71.214.60.49-20121024095205

Unicorns have spells that provide light. Twilight was just using a variation of the flashlight spell used by other characters. The second image down shows Twilight casting a really powerful spell, which would fall under the extreme exertion exception/justification, and may have been thrown in there just to add emphasis. Having Twilight groan more wouldn't have made the increased effort as obvious.

Some spells do have a visual component, but those are either very powerful or have some kind of physical effect on the world. The wing granting spell made a cocoon around Rarity, the flashlight spell specifically creates light, and the force beams are standard scifi/fantasy energy beams. Twilight's magic meltdowns seem to be visible to the characters, but since she's having trouble controlling her magic it wouldn't be surprising for her to generate visible light when she usually wouldn't. Most of the time, the auras  just seem to be for audience convience. The characters certainly can't identify unicorns by aura color.

I'd theorize that visible light in spells without a visible component is the result of sloppy or uncontrolled spell casting, but that is blatant speculating.

I'm planning to rewatch the first two seasons before the third comes out, but I'll be surprised if I find anything that shows the ponies seeing to day to day spell casting.