资料来源 : Free On-Line Dictionary of Computing

true colour
     
         A system where the red, green, and blue components
        of a colour are stored in {display memory}, as opposed to
        storing {logical colours} and using a {colour palette} to
        convert them to red, green, blue components.
     
        The advantage of true colour over a palette is that it does
        not restrict the range of colours which can be displayed on
        screen simultaneously.  For example, if eight bits are used to
        store each component of each {pixel} then a total of 2^24
        (about 17 million) different colours can be displayed at once
        which would require a (very expensive) palette with 3 * 2^24
        bytes (about 50 megabytes) of memory.
     
        The disadvantage of true colour is that image transformations
        which would normally be done by changing the palette must be
        done to every pixel of the image which can be much slower.
     
        Compare {high colour}.
     
        (1996-03-24)