Inability to discern between CSS and Sass functions

[blackfalcon]

Experimental CSS feature uses the same syntax as a Sass function. When using this new syntax, libsass throws an error as the input is not consistent with the expectations of the Sass function.

The following is the proposed experimental CSS syntax:

.class {
  filter: grayscale(50%);
}

When using this with libsass, the following error is returned:

argument `$color` of `grayscale($color)` must be a color

The only way around this currently is to use a mixin to generate the CSS rules.

[nschonni]

Dupe of #151

[blackfalcon]

So it is.