For this trick, you'll need two silk scarves of different colors. Start the trick by concealing one silk scarf in your closed fist, and come on stage with the other silk in your other hand. Explain to the audience that you'll be changing the color of the silk by passing it through your hand, then stuff the unconcealed silk into your fist. As you push it into your first, draw the concealed silk out so that the silk appears to be changing colors.
One of the most common tools in silk magic is a thumb tip, a hollow rubber cylinder that looks like your thumb. You can use a thumb tip to "disappear" magic silks by wearing the thumb tip on stage, taking it off and placing it in your fist without the audience knowing, then stuffing the silk into the thumb tip when it looks like you're stuffing it into your fist. Use slight of hand to conceal the thumb tip, and show your open hands to the audience to prove that you've really made the silk disappear.
You'll need a specific item for this trick -- a rope-to-silk prop, which is a silk that has a rope-like sheath that can be expanded to fit over the silk. To perform the trick, hold the rope end in your fist, and let the silk dangle beneath your hand. Then hold the top of the rope in one hand, and pull the sheath down over the silk to create the illusions that the silk is changing to rope.
The rose-to-silk trick is another common magic silk trick that only requires a red silk and some practice. For this trick, the magician folds the flower of a rose from the silk using slight of hand, and places it in her pocket or on a flower stem. You can also fold the silk into a rose before coming on stage, and then shake it out into a silk at a dramatic moment when you need the prop.