title: styled-components, polished and themes
body: <p>I am trying Styled-components in a simple React project, I have a theme object that is passed to the component so I can do:</p>
  
  <p><code>background-color: ${props =&gt; props.theme.primary};</code></p>
  
  <p>I am also using Polished to modify the passed values, so a button uses a darker version of the color as an outline. I can do this with:</p>
  
  <p><code>border: 1px solid ${darken(0.05, '#00823b')};</code></p>
  
  <p>But I need the color value to be from the theme, how do I go about passing the theme properties in?</p>
  
  <p>Thanks!</p>