which trick has a blue card and all red cards by oscar owens

The trick you’re describing is most likely Oscar Owen’s blue/red card color- change or color-swap routine, where a card appears to switch between a blue- backed and red-backed deck. In one of his reveals, he shows the setup with alternating red and blue cards and the effect of ending with “all red” or “all blue” cards depending on the selection.

What it is

Oscar Owen has multiple related card effects built around the same visual idea: a chosen card looks like the only one with a different-colored back, or the deck appears to transform from mixed colors into all one color. The performance in question is probably the “deceptive card trick” where the spectator ends up with the only blue card, while the rest appear red.

Closest match

The closest match from the available material is “The Most DECEPTIVE Card Trick Ever Created | Revealed” by Oscar, which uses alternating red and blue cards and then creates the illusion that the selected card is the only differently colored one.

Simple takeaway

So, if you meant the trick with one blue card and the rest red , it’s the blue/red color-change or color-swap card trick from Oscar Owen’s magic content.