Maps entries from the current logical palette to the system palette.
A logical color palette acts as a buffer between color-intensive applications and the system, allowing an application to use as many colors as needed without interfering with its own displayed colors or with colors displayed by other windows.
When a window has the input focus and calls RealizePalette, Windows ensures that the window will display all the requested colors, up to the maximum number simultaneously available on the screen. Windows also displays colors not found in the window's palette by matching them to available colors.
In addition, Windows matches the colors requested by inactive windows that call the function as closely as possible to the available colors. This significantly reduces undesirable changes in the colors displayed in inactive windows.