Change sidebar widget, interstitial, and/or scrolling navigation background colors (Presidio)

Use these code snippets to adjust the gray color of your sidebar widgets and interstitial backgrounds in the Presidio theme. It also includes code snippets to change the color of the Instagram feed background, and your scrolling navigation background. NOTE: The code below will not change the color of the Text widget in your sidebar. To adjust text widget colors, use this code hack.

Here is a quick demo to show you this Code Hack in action:

And here’s the code you need to implement it: