Vähennysväriavaruuden

Vähennysväriavaruus, often translated as subtractive color space, is a model used to describe how colors are created by absorbing certain wavelengths of light and reflecting others. Unlike additive color spaces, which combine light to create colors, subtractive color spaces start with a white surface, which reflects all visible wavelengths, and then subtract colors by adding pigments or dyes. The primary colors in a subtractive system are typically cyan, magenta, and yellow (CMY).

When these primary colors are mixed, they absorb different parts of the light spectrum. Cyan absorbs red light, magenta absorbs green light, and yellow absorbs blue light. The combination of all three primary colors ideally results in black, as all wavelengths of light are absorbed. In practice, a pure black is often achieved by adding black ink, known as key, to create the CMYK model, which is widely used in printing.

Subtractive color spaces are fundamental to processes such as painting, printing, and dyeing. In printing, inks are applied to a white substrate like paper. The inks act as filters, absorbing specific wavelengths of light and reflecting the remaining wavelengths, which our eyes perceive as color. The limitations of pigment purity mean that a perfect black is rarely achieved with just CMY, hence the addition of K (black) for richer dark tones and sharper text. Understanding subtractive color is crucial for achieving accurate color reproduction in these applications.