Reflected color is what we see when light bounces off a surface, like ink on paper. When we print something, we use CMYK which is a subtractive color model. The ink absorbs certain wavelengths of light and reflects others. For example, if you want to print blue, the printer mixes cyan and magenta ink. Cyan absorbs red, and magenta absorbs green, leaving blue to reflect back to your eyes.
Projected color is what we see on screens like phones or computers. This is RGB (Red, Green, Blue), an additive color model. In this case, colors are created by mixing light directly. For example, when you see red on a screen, the red light channel is on full blast while green and blue are off. To make white, all three colors are at full intensity, and to make black, none of the lights are on.
In 24-bit color, each pixel in an image is made up of three color channels: red, green, and blue. Each channel has 8 bits, which means it can have 256 different values (2^8). So, combining these three channels gives us over 16 million possible colors. This is the kind of color you’d see in high-quality photos where you need smooth transitions between shades, like in a sunset or a detailed portrait.
Indexed color, on the other hand, is more efficient but limited. Instead of storing the exact color for every pixel, the image uses a color palette—a list of up to 256 colors. Each pixel doesn’t store the color itself but just an index pointing to the right color in the palette. This method is used for simpler images with fewer colors, like logos or web graphics because it saves file space. However, it’s not good for images that need a lot of detail, like photos with complex shading.
For example, 24-bit color: A high-res photo where you want all the shades and gradients to look smooth and natural. Additionally, indexed color: A GIF of a logo, where only a few colors are needed to keep the file size small.
For me, In graphic design, you need to know when to use each system. Printing uses reflected color (CMYK), and screens use projected color (RGB).
