All colours are specified in terms of a 24-bit colour value, represented by the class TRgb
. This 24 bit value is mapped down to device-level values by the graphics device or printer driver.
Note that:
Colours can be specified logically (for example, window background colour) as well as physically. The UI Graphics Utilities API contains a list of logical colours (TLogicalColor
) and means to convert them into RGB values.
The window server defines display modes that define possible different colour resolutions. In each display mode, as enumerated by TDisplayMode
, a unique index can represent each physical colour supported. TRgb
can map such indices onto a full RGB value.