[dropcap]H[/dropcap]ide YouTube Logo:- By default, a YouTube logo and link appears in the video control bar. The parameter modestbranding set to 1 hides this. A link to YouTube still appears in the title bar.
?modestbranding=1



Note:- This only works if you use it as the first parameter after the video id

HOW TO CUSTOMIZE YOUTUBE PLAYER EMBEDS:-

• Turn off Title & Ratings : &showinfo=0


• Turn off Search: &showsearch=0


• Turn on Related Videos: &rel=1


• Turn off Annotations: &iv_load_policy=3


• Force Closed Captions: &cc_load_policy=1


• Turn on AutoPlay (not recommended): &autoplay=1


• Loop Playback: &loop=1


• Remove Full Screen Option: &fs=0

How to Customize YouTube Video Quality :-

• Show in High-Definition 720p: &hd=1


• Show in High-Quality: &ap=%2526fmt%3D18

theme & color :-
This parameter indicates whether the embedded player will display player controls (like a play button or volume control) within a dark or light control bar.

&color=white
&theme=light ( Default is dark/black video player theme)

Show Captions

By default, YouTube will use the user’s selected closed captioning option. However, the parameter cc_load_policy set to 1 will override this.

Example :- 

How To Embed a Custom YouTube Player

https://www.youtube.com/watch?v=j-K3IGIMF9M

Turn Off Youtube Related Videos

https://www.youtube.com/watch?v=TGg9cKDljnk
Source: YouTube