Modify the color conversion
Round number instead truncate at RGB24_TO_VDPCOLOR
* \param color
* RGB 24 bits color
*/
-#define RGB24_TO_VDPCOLOR(color) (((color >> ((2 * 8) + 4)) & VDPPALETTE_REDMASK) | ((color >> ((1 * 4) + 4)) & VDPPALETTE_GREENMASK) | ((color << 4) & VDPPALETTE_BLUEMASK))
+#define RGB24_TO_VDPCOLOR(color) ((((color + 0x100000) >> ((2 * 8) + 4)) & VDPPALETTE_REDMASK) | (((color + 0x1000) >> ((1 * 4) + 4)) & VDPPALETTE_GREENMASK) | (((color + 0x10) << 4) & VDPPALETTE_BLUEMASK))
/**
