Is Alicorn magic dark magic?

[Senko 459]

I've been rewatching the series for another project and I just noticed something. King Sombra's dark magic is a sort of greenish purple both his own personal glow and the magic used to get things to respond like his door to your darkest fear or the crystal Celestia uses the same greenish purple glow to make dark crystals grow. However in Season 4 Zecora say's her potion will only respond to Alicorn magic and we see Twilight use the same greenish purple magic to turn the potion white.

 

 

[SDP40F amtrak 2,447]

Hmm I think so but depend who can control themselves 

[Will Guide 21,359]

There might have been evil Alicorns far in the past that not even Celestia or Luna might not even have known about.

[Wonderbolt Slipstream 263]

I think it changes on how they use their magic, I think there may be multiple types of magic. An example would be light magic (which we haven't seen), normal magic (which is the basic magic), and dark magic (the sick purple and green type).