If you've ever bought a new pair of jeans and found that they've Smurf-ified your hands, purse, shirt, or (the horror)white couch, here's a good tip for you: wash them with vinegar. Throw them in the wash machine alone (you don't want them to dye anything else). Set your machine on the cold cycle, and when it's full of water, pour in a cup or so of white vinegar. I should confess that when I say "or so," what I actually mean is "I have no idea, but I upended my quart-sized jug and gave it a glug or two." Let the cycle run (don't worry: the smell will be gone once it finishes), and then hang your pants to dry. The vinegar will set the color in your jeans, meaning you can bravely sit wherever you want, sans dye-anxiety.
PS: Also in laundry news, I used my Dreft laundry spray for the first time, and I can report that it does excellent work on blue popsicle spills (yes, I'm thirty, but in my defense, it was the Fourth of July).