Effect: You show a Zip-Loc bag filled with slips of paper. Spectator draws several slips to show they are all random names of colors. You give the bag a shake and close your eyes/are blindfolded/etc. Spectator draws a final slip without looking. Without ever opening your eyes/removing the blindfold/whatever, you name the color name on the spectator's slip.
Secret: You use a force bag to ensure that you know ahead of time what color the spectator will pick.
You can purchase force bags, but you can make one for practically no money or time investment by taking 2 Zip-Loc sandwich bags, turning one inside out, inserting it in the other bag, then zipping one flap from the inside out bag to a flap of the right-side out bag. When done correctly, you will create a two-compartment bag. Fill the compartment on the side of the bag that will face the spectator (the "fair" side) with slips of paper with random color names written on them. Fill the other compartment (the "force" side) with slips of paper that all have the same color name on them (I'll use "Brown" for this example). You are ready to present the trick.
Presentation: Open the "fair side" of the bag by inserting your thumb and forefinger of both hands into the corners of the mouth of the force bag, pinching the dividing flap of the bag back against the back side. Invite the spectator to draw several slips of paper to verify the color names are random. Close the bag and give it a shake to "mix up" the slips. When you re-open the bag, open the "force side", again with your thumb and forefingers, and pinch the dividing flap forward to reveal only the slips with "Brown" on them. Close your eyes(or allow yourself to be blindfolded), then have your spectator draw from the "force side" without looking. They will draw a slip with "Brown" on it. Without removing the blindfold/opening your eyes, have the spectator look at the color drawn and concentrate on it, then finally reveal the color.
You can play this seriously or for laughs (by forcing "Clear" as the color, for example), and of course can substitute names of famous people or food items or whatever you find most appropriate. The possibilities for mental magic using a force bag are practically endless! Of course, NEVER REPEAT THE TRICK FOR THE SAME GROUP OF SPECTATORS!