I use them until they are almost dark purple. I use fresh Color Catchers on more precious quilts and reuse the sheets on scrappy quilts. Sometimes I have 8 or 9 used ones when washing quilts. Yesterday, I washed a baby quilt with lots of white, Kona berry and teal in it, through in the used color catchers and the quilt was fine and the color catchers ere the same color as when I started - light purple. I never wash my quilts without the sheets. I find organic navy blue the worst for bleeding.