the most effective for me is a riffle passlol i'm not kidding its extremely visual pretty angle proof and doesn't look suspicious. Another that comes to mind is steve draun's midnight shift used as a color change (less angle proof but looks so squeaky clean)
I would love to see your Riffle Pass someday!
For the most effective color change I would definitely go for the Twirl Change, no doubt. Having the card completely separated from the deck gives the best reactions by far! Therefore it beats its brother the Shapeshifter, and the Erdnase, and because it's angle proof too it beats most other changes out there at anytime!
