How to Make Red Paint Darker

Red is one of the primary colors, which means it cannot be made from any other color. Green, for example, is a combination of yellow and blue, the other two primary colors. Spectral red, the color found in the rainbow is a pure red. Shades of red are developed by mixing in other colors, white and black. If you would like to darken the color of red paint, it's a simple but tricky process — because you're creating a color that might be difficult to reproduce. However, it's simple because you're adding only one color to the red.

Here's a step-by-step guide to making red paint darker.

Measure 4 tbsp. of the red paint into a disposable container. Add 1/4 tsp. of black paint and stir well with a craft stick. Paint the darker red paint onto some poster board.

Let the paint on the poster board so you see its final color; most paints are darker when dry. Make a note on the poster board, indicating that this sample is "1 to 48" or one part black paint to 48 parts red paint. One tablespoon equals three teaspoons. One teaspoon equals four quarter-teaspoons. So four tablespoons equals 48 quarter-teaspoons.

Make a darker blend to compare with the first. Measure another 4 tbsp. of red paint into another container. Add 1/2 tsp. of black paint and stir well. Paint the poster board. Mark next to that it was "1 to 24."

Make more test batches, as desired. For each batch, add an additional 1/4 tsp. of black paint to 4 tbsp. of red paint. Use a new container for each batch. Test the color on poster board, as before, and mark each color with the mix ratio.

When you think you've found the color you want, paint a sample on the surface you will be painting. Different surfaces will show colors differently, so it's important to see what the paint looks like on the actual surface.

Let the paint sample dry, then check the color in different levels of light. If it dries to the color you want, you're finished. If it's too light, go back and make another batch but add only an additional 1/8 tsp. of black paint. If it's too dark, use the last formula you used but subtract 1/8 tsp. of black paint. For example, if you used 3/4 tsp. (6/8 tsp.) of black paint to 4 tbsp. of red, use 5/8 tsp. of black paint.