diff --git a/mixins.js b/mixins.js
index 7fd3d28..a95e9a0 100644
--- a/mixins.js
+++ b/mixins.js
@@ -9,9 +9,9 @@ function defineColor(mixin, name, hex) {
   obj[name] = hex;
   // need to convert hue to string otherwise postcss (is it postcss?) appends
   // 'px' to the property's value.
-  obj[`${name}-h`] = hue.toString();
-  obj[`${name}-s`] = `${sat}%`;
-  obj[`${name}-l`] = `${light}%`;
+  obj[`${name}__h`] = hue.toString();
+  obj[`${name}__s`] = `${sat}%`;
+  obj[`${name}__l`] = `${light}%`;
   return obj;
 }