If Jackson is making a three-color brochure, he is likely using the subtractive color model. This is commonly used in printing, where colors are created by combining inks that absorb (subtract) certain wavelengths of light. The primary colors in the subtractive model are cyan, magenta, yellow, and black (CMYK).
The additive color model, on the other hand, is used for digital screens (like computers and TVs) where colors are created by mixing light (RGB: red, green, blue).
Therefore, the correct answer is subtractive.