title: CSS - possible to get current "value" and "add" to it?
body: <p>In my css, I have a table with zebra striping. e.g. white and light-blue.</p>
  
  <p>Lets say I have three columns... what I'd like to do is be able to make maintain the zebra striping, and within css (no javascript) add shading/make the blues darker for each column.</p>
  
  <p>Is that possible? Something like getting the "current" background color #AABBCC and then Adding #000011 to the current color to give me #AABBDD...</p>
  
  <p>No idea if this is even possible, so just wondering. I'm just being lazy, as I don't want to have to redefine my zebra striping for every column/column group I may have.</p>
  
  <p>Thanks</p>