Simple substitution no magic I`m afraid :-)
If you note the cards you`ll see that they change all of them and take one away. As your only looking for your card you don`t notice the change. Like this-
Start K(h) Q(d) J(s) Q(c) J(h) K(c)
you choose K(h)
Finish K(d) Q(h) J(c) Q(s) K(s)
now you see five red and black cards but not the one you picked.
Neat quick trick the first time you see it tho !