I want to build a theme with some options. One for example is to pick one of a few pre-defined colors. I was thinking of something like that:

{
  theme_border_color: "green"
}

But I couldn’t find anything like that in existing themes. So I was wondering if something like that is even possible (and if yes how would I access that string in my .sublime-theme)

Im not to happy with the other solution

{
  theme_border_color_green: true
}

Have a look at Aprosopo theme by faceless, the theme is highly configurable with nice menu