typedef unsigned char GifByteType;

typedef struct GifColorType
{
    GifByteType Red, Green, Blue;
} GifColorType;

typedef struct ColorMapObject
{
    int ColorCount;                        
    int BitsPerPixel;                    
    GifColorType *Colors;                
} ColorMapObject;

    ...............

    BitsPerPixel = 8;

    ColorMap = (ColorMapObject *)malloc(sizeof(ColorMapObject));        

    if(ColorMap == (ColorMapObject *) NULL)                             
    {
        FATFileClose(fd);                                                

        return 0;        
    }

    ColorMap->Colors = (GifColorType *)calloc(1 << BitsPerPixel, sizeof(GifColorType));    

    if(ColorMap->Colors == (GifColorType *) NULL)                         
    {
        free((ColorMapObject *)ColorMap);                                  
        FATFileClose(fd);                                                

        return 0;                                                        
    }

    ..........