My emojis are only showing up as yellow. How do I either get the old emojis back or how do I toggle the "diversity" option?

The color emojis are gone unless Apple decides they want to put them back. You can provide feedback here: http://www.apple.com/feedback/

BTW, I pre-typed all of the old emojis before updating. Even those are yellow as well now.

-Ethan

Only certain yellow faced emojis can be changed & you do this by long pressing on the emoji & you'll see a pop up with various skin colours, just click on the skin colour you'd like.

All of my previous emojis have been changed to the yellow people. My third party keyboards do not allow for the choice of skin so I am stuck with all yellow blond people...would love to have the old emojis back! Is there a way??????

No, unfortunately not. As said above by Doctor9fan, you can tap and hold some emojis for different skin colors.

-Ethan