title: Creating an animated radial gradient in Processing, similar to the Solar Weather App
body: <p>I'm trying to create a radial gradient in Processing, and animate the gradient to give it a slow breathing effect. The gradient needs to oscillate between two color sets - an effect seen in Solar, the iOS weather app. </p>
  
  <p>I found the <a href="https://stackoverflow.com/questions/14920768/creating-an-animated-gradient-background-similar-to-the-solar-weather-applicatio">same question</a> asked for xCode, but I'd like to get some pointers for Processing. </p>
  
  <p>Here's an image that explains my question better:
  <img src="https://i.stack.imgur.com/UUfZZ.jpg" alt="enter image description here"></p>
  
  <p>I stumbled on the 'Radial Gradient' <a href="http://processing.org/examples/radialgradient.html" rel="nofollow noreferrer">example code</a>, but I'm not quite sure how to proceed with animating the gradient, and creating the hole in the center to form the donut shape. </p>
  
  <p>Any sample code, pointers, suggestions would be greatly appreciated! Thanks!</p>