I recently needed some rather odd colored teal buttons for a shirt, and could not found the appropriate shade at the fabric store. I remembered I had a zillion buttons at home from the time I bought a bag of buttons from Fabric Mart so I bought some teal Rit dye instead.
1.Select different types of buttons to dye.
I chose white fabric covered buttons and plastic buttons: gray and 2 different types of tortoiseshell/mottled brown. I didn't bother test dying, as I have lots of these buttons. I needed a grayish teal so I chose to dye brown and gray. I dyed about 10 buttons of each type.
2. Put 1-2 Tablespoons of Rit Dye in a small baggie. Add about 1 cup of hot water and swish until the Dye is dissolved.
3. Add the buttons and swish them around for about 5 minutes, or until they look a bit darker than you want.
4. Rinse the buttons in a strainer in the sink until the water runs clear. If they are not dark enough you can put them back in the dye.
5. Wash and dry the buttons in a mesh laundry bag.
One of the button types (one of the mottled brown), turned out to be a perfect match for my fabric. The other 2 plastic types turned out well also and I will save them for another time when I need teal buttons. The white fabric covered buttons washed out when in the washing machine - I think the fabric must be polyester.
I think this works best if you have masses of buttons that you can dye without worrying about the outcome. I got mine by purchasing a 4 lb. bag of buttons from FabricMart Fabrics for $5.00 (I'm not associated). There were LOTS of duplicates - 10-50 of many different types of buttons. I've seen bulk buttons sold elsewhere also.
I hope to get a picture attached someday, but if I wait I may never post the hint - and I think it might come in handy for someone. I also cannot attest to the longevity of the dye. They didn't fade in the washing machine so I think the color will last.