YouTube defaulted <iframe> embed code for sharing videos on websites. You can still use the old <object> embed code. This new embed code lets viewers to watch embedded video in Flash or HTML5 players. If viewers browser didn’t support HTML5, YouTube use Flash. In mobile devices it will use built-in player instead of Flash or HTML5, This is the additional feature of new embed code.
YouTube new embed options:
YouTube old embed options:
If you want to use old <object> embed code, just select use old embed code checkbox in embed options. Earlier color selection makes player to look in different colors, but now color selection is removed to display YouTube player in unique color, the silver. Check more here of you are using YouTube API.