The following page has two videos embedded from YouTube – the clips are identical but the skin of the YouTube player containing these videos is different in both cases.
The first YouTube video player uses the default colors (metallic white) while the video player for the second video uses a dark theme - the frame itself is black while the video control bar is red in color.
If you use IFRAMEs to embed YouTube videos, you can easily change the color of the YouTube Video Player by adding a new parameter called theme to the URL.
For the dark (black) player, set the theme value to dark else set it to light for using default colors with the YouTube Player.
For Light (White) Player:
For Dark (Black) Player:
This new theme option for setting colors is only available for the IFRAME version and not for the old OBJECT based embed codes.
Shannon Behrens of YouTube says that YouTube would be switching to the dark video player for all embeds in the next few days. That means you’ll have to add the theme=light option manually to all your existing embeds in case you wish to use the existing white skin for the player.