You have to realize that while the visual phenomenon is happening, the colors are moving, blinking, blurring in and out of their vivid primary colors, morphing, changing. The outlines are changing, from dark to bright gold light.
This is a sketch I made while having right-eye migraine aura today. It is a form of Scintillating Scotoma -- some good illustrations at the Wikipedia link, by the way -- sometimes called "fortification spectra" or teichopsia, according to this link. I scanned it and prettied it up some with MS Paint. Picture this in motion, overlaid on everything else I was trying to look at.
Probably this was triggered by glare while working the parts counter, looking past the customer to the bright sky outside. As soon as I could, I took a naproxen sodium tablet, had another swig of coffee (caffeine may trigger migraine in some people, but for me it is the drug of choice), and iced my face. The phenomenon is really quite beautiful. Duration of visual disturbance this time was about forty minutes from start as a bright dot in the center of vision to being a dull, ignorable border on the right. Now, three hours later, I just feel stupider than usual and somewhat out of alignment with my physical self.
Why does this happen?! The Mayo Clinic says, "It's believed that the visual aura that may accompany migraine is like
an electrical or chemical wave that moves across the part of your brain
that processes visual signals (visual cortex). As the wave spreads, it
may cause these visual hallucinations." What that means, I do not know.
Also: Why ME?! Well, first you have to have the right genetic background . . . Thanks, Mom!