Combine equal parts red, blue, and green food coloring until the color appears black
Add a tiny amount of black cocoa powder or activated charcoal for a deeper black shade
Use gel food coloring for stronger color concentration
Mix in very small amounts at a time to avoid over-darkening
Adjust with more blue or green if the mixture looks too red
Let the mixture sit briefly to see the final color before adding more
Use black gel paste if available for the darkest result