I have this old baby doll shirt and the color is worn...looks greyish blue on the lace parts and white on the entirety. It's supposed to be completely white. I have been wanting a dark brown shirt but I'm broke at the moment so I figured I could try to dye it myself. Anyways, I googled it and I can use coffee grounds to dye it but I wonder how dark it can get. Can I get it a dark as the actual coffee color? Seems like it would turn out tan to me. Also, I don't know what the material of the shirt is made out of, I guess the care tag fell off. How am I supposed to test a spot or know if it's a dye-able fabric? I don't want to ruin it.I have this old baby doll shirt and the color is worn...looks greyish blue on the lace parts and white on the entirety. It's supposed to be completely white. I have been wanting a dark brown shirt but I'm broke at the moment so I figured I could try to dye it myself. Anyways, I googled it and I can use coffee grounds to dye it but I wonder how dark it can get. Can I get it a dark as the actual coffee color? Seems like it would turn out tan to me. Also, I don't know what the material of the shirt is made out of, I guess the care tag fell off. How am I supposed to test a spot or know if it's a dye-able fabric? I don't want to ruin it.

Food color dye in water might work.