The yellow "Most recent" button at the top of the screen--

[EarlG]

2. Are you using Skinner Mode?

The option to change the color is not available in Skinner Mode I'm afraid. The idea for that layout is to keep it as close as possible to the previous layout, and that's the color which was used previously.

If you are using Default Mode or Night Mode (and if you don't know what I'm talking about, that means you're using Default Mode) you don't have to stick with the flashing yellow button.

Go to My Stuff > Account Settings

Scroll down to the "My Stuff" notification settings section and you will find the options to change it there. Don't forget to hit "Save all settings" when you're done.