NAME
    GetRGB4 -- Inquire value of entry in ColorMap.

SYNOPSIS
    value = GetRGB4( colormap, entry )
      d0              a0       d0

    ULONG GetRGB4(struct ColorMap *, LONG);

FUNCTION
    Read and format a value from the ColorMap.

INPUTS
    colormap - pointer to ColorMap structure
    entry - index into colormap

RESULT
    returns -1 if no valid entry
    return UWORD RGB value 4 bits per gun right justified

NOTE
    Intuition's DisplayBeep() changes color 0. Reading Color 0 during a
    DisplayBeep() will lead to incorrect results.

BUGS

SEE ALSO
    SetRGB4() LoadRGB4() GetColorMap() FreeColorMap() graphics/view.h