title: what's the meaning of color[0-15] in urxvt settings?
body: <p>First, I've searched the topics on google.com, but not help a lot.</p>
  
  <p>I've configured my urxvt using some color themes, but it's really hurt my eyes. So, I decided to create my own using some Vim color pallete. I really need to know what's the meaning of color0 - color15 in urxvt .Xdefaults or .Xresources setting. What's the purpose of those colors? Anyone knows?</p>