How to define a group of variables in stylus? - stylus

Question

I was wondering if there was a way to switch between two groups of variable definitions. For example, to change the color theme:
$my-blue = #1876d3
$my-white = #f6f6f6
blue-on-white()
$primary-color = $my-blue
$secondary-color = $my-white
white-on-blue()
$primary-color = $my-white
$secondary-color = $my-blue
// Now I could go back and forth between both schemes to see which one I prefer
blue-on-white()
// white-on-blue()
I've tried the above approach using mixins, but it doesn't work with variables.

Answer 1

Maybe there is another or better way to do but I found a solution using hashes: http://stylus-lang.com/docs/hashes.html.
Stylus
blue = #1876d3
white = #f6f6f6
blue-on-white = {
primary-color : blue,
secondary-color : white
}
white-on-blue = {
primary-color : white,
secondary-color : blue
}
h1
color blue-on-white[primary-color];
background-color blue-on-white[secondary-color];
h2
color white-on-blue[primary-color];
background-color white-on-blue[secondary-color];
Compiled CSS
h1 {
color: #1876d3;
background-color: #f6f6f6;
}
h2 {
color: #f6f6f6;
background-color: #1876d3;
}