<P> The DVD - Video and Blu - ray Disc standards support a bit depth of 8 - bits per color in YCbCr with 4: 2: 0 chroma subsampling . YCbCr can be losslessly converted to RGB . </P> <P> Macintosh systems refer to 24 - bit color as "millions of colors". The term "True color" is sometime used to mean what this article is calling "Direct color". It is also often used to refer to all color depths greater or equal to 24 . </P> <P> Deep color consists of a billion or more colors, 2 is 1.073 billion . Color depths of 30, 36, and 48 bits per pixel are in use, also referred to as 10, 12, or 16 bits per RGB channel / sample / component . Often an alpha channel of the same size is added, resulting in 40, 48, or 64 bits used for each pixel . </P> <P> Some earlier systems placed three 10 - bit channels in a 32 - bit word, with 2 bits unused (or used as a 4 - level alpha channel). The Cineon file format that was popular for motion pictures used this . Some SGI systems had 10 (or more) bit D / A converters for the video signal and could be set up to interpret data stored this way for display . BMP files define this as one of its formats, and it is called "HiColor" by Microsoft . </P>

What is the color depth of a deep color photo