It's kind of hard to say. There's not a whole lot you can do with a Zekrom shiny since it's literally the Deep Black/Black Yin Pokemon, you don't have much for color options lol (though this is fine).
In Gen 5 I prefer the original to the shiny since it's a real black and not the like....dark gray-green the shiny is. But after Gen 5 OG Zekrom is a medium or dark gray color for some reason and that narrows things a lot, to the point that idk if I have preference.
Would love to see it become black again, and for the difference between the shiny and non-shiny forms to be the color of the electricity pulsing within it. I mean, it does that already (the shiny is green electricity while the non-shiny is blue), but I want both to have the black color, and there's other colors that could be cool for the electricity too.
“No, I... I have to be strong. Everyone expects me to."