A printer driver must provide support for translating logical colors (RGB values) to physical colors. For printers with color palettes, the printer driver must provide additional information in its GDIINFO structure.
GDI calls the ColorInfo function to translate physical and logical color representations. This function translates in both directions, that is, from physical to logical and from logical to physical. When given a logical color, the function returns the nearest physical color. When given a physical color, the function returns the logical color that best describes that color.
This function supports the GDI function GetNearestColor.
GDI ignores the color palette members if the RC_PALETTE value is not set in the dpRaster member. However, they must be present (and accounted for in the length returned by Enable) if the driver is version 3.x.