I washed my colored clothing together and now a few items have black color patches on them. Is there any way to remove those black patches?
When the color is only in a few places, it usually means the black color bled directly onto the other items, probably while the washer was in the final spin cycle and the items were pressed together. If everything turned the same uniform color, that would indicate dye transfer, where dye runs off of one item and migrates through the wash or rinse water onto other items. In either situation, you should be able to restore any bleachable items to their proper color with a bleach soaking solution, but first you need to figure out which items are safely bleachable.
Begin by checking the care labels and be sure you avoid bleaching any garments made of wool, silk, mohair, spandex, and leather. For the colored items, check for colorfastness to bleach with this simple bleachability test: dilute 1 ½ teaspoons Clorox® Regular Bleach2 in ¼ cup water; apply a drop of this solution to a hidden part of each item (like a hem, cuff, collar, or inside seam); wait 1 minute then blot dry; no color change means the item can be safely bleached, and you can try a bleach soaking solution to strip off the unwanted black color.
To make the bleach soaking solution, add 3 tablespoons Clorox® Regular Bleach2 to 1 gallon cool water. Fully submerge the items for up to 5 minutes. Thoroughly rinse each garment and then allow them to air dry. Hopefully the black color will be gone, but if it is lighter, then repeat the bleach soak again.