This function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.

Returns the first key in the database. Note that no particular order is guaranteed since the database may be built using a hash table, which doesn't guarantee any ordering.

蛁 If you need to seek and write to the stream, it does not make sense to use this function, because the stream it returns is not guaranteed to be bound to the same resource as the original stream.