At events like prereleases, where newer players face experienced ones, I see new players get surprised by all the different opportunities to interact during combat
(The Marvel version of Thor is more red-white.) My best guess is that we just made a cool Thor and Mjlnir (Thor's hammer), and they just got stuck in the color that best matched the mechanical flavor
Obviously these may be a miss for your format for other reasons (power, archetype mismatch, rarity, don't run planeswalkers etc) but here's a few that I found interesting, divided by broad category rather than color: Actual Modal Dual Faced Cards: While I'm still not done reading Cosima, God of the Voyage (I'm on chapter 2, the language is a bit dense) these cards are ones I do like both sides of
12 Gadget Hackwrench - Brilliant Bosun Card 217/204 EN.6, Sapphire Ink Alongside Chip and Dale's Enchanted card comes their brilliant inventor, Gadget Hackwrench