title: iOS - CorePlot gradient overlays the others
body: <p>I'm using CorePlot version 1.2 for my app, and for my reasons, i need to keep this version.</p>
  <p>When i plot the graph, i've notice that the gradient color below one of my scatter plot overlays the other plot.</p>
  <p>More specific the colors of others serie are like &quot;darkened&quot; under the gradient shadow and more brilliant outside that area.</p>
  <p>See the pic for more details</p>
  <p><a href="https://i.stack.imgur.com/E8n12.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E8n12.png" alt="the plot" /></a><br />
  <sub>(source: <a href="http://www.mathnormal.altervista.org/gradientOverl.png" rel="nofollow noreferrer">altervista.org</a>)</sub></p>
  <p>I would like to have the same color for the others serie(also under the gradient shadow) but i'm not able to solve this problem.</p>
  <p>Thanks in advance.</p>