When the maximum amount of color is added to video, by what factor does its size increase?

When color is added to video, the increase in size is related to how color information is encoded in relation to luminance (brightness) information. In standard video formats, grayscale images are usually represented by a single channel, which signifies luminance. When introducing color, the video typically utilizes multiple channels to represent different aspects of the color.

In most common formats, a full-color image is represented using three separate channels—red, green, and blue (RGB). Each of these channels holds information about color intensity, which means that for every pixel in a grayscale image (which uses only one channel), three channels are now required to represent the full color. Thus, the size of the video increases by a factor of three times the luminance size for the RGB channels alone.

However, if we consider additional chroma information, such as in formats that include alpha channels or various color spaces (like YUV, which might use additional channels for color sub-sampling), the size can increase even further.

In a scenario where full color is accounted for, and specifically when going from a monochrome format (1 channel) to full RGB color format (3 channels), the increase in size for full, true-color video usually leads to a total increase by a