Let me know if you find them. I too prefer black for a no-stain solution. They do fade, but if still in good shape you can actually refresh them with some black RIT dye. Try Tuesday Morning; they often have unusual stuff.

I hated when dishcloths would get that sour smell. I used to boil mine after dinner dishes were done and never used them more than one day. I switched to Swedish dishcloths. Put them in the dishwasher with my dishes each evening. Fresh and clean the following morning. Last about 4 months before I throw it away and start with a fresh dishcloth. Antimicrobial, so they never get that awful smell.

Found that they do make them in black.

Amazon.com: SCANDISH - Black Swedish Dishcloths - Set of 3 - Swedish Dish Cloths - Made in Sweden : Health & Household

For drying dishes I fell in love with the H2O dishcloth. Actually love the whole line of products, but they do not come in black.