rjackson/bootstrap-sass — comment on commit 2ae648370e0666565253da9a72bae48563d741e2
File: vendor/assets/stylesheets/bootstrap/mixins.css.scss line 169
By rjackson:

The function is defined in ruby with underscores, but it becomes callable in scss/sass with either hyphens or underscores. I just pushed another commit to change it to underscores.

The function gets called during sass's compile stage, and the resulting css output (in both development and production) is:

```css
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#FF333333', endColorstr='#FF222222', GradientType=0);
```