The official sleeves are pretty nice, although I don't like the blue and red, cause you can't really read them then ;O
Umm one side of the blue and red sleeves is clear.The card should be inserted where the back of the card should face on the colored side of the sleeves.
What would be the point of having the hidden effects on those certain cards then? Dur.
It's just a cool effect you get with the card. It's not like they have a rule "Flip card in sleeve to show hidden power".
Yeah but then theres no point in ever having the special effect if you never see it.