Autocomplete suggestions for HEX colors in the current document


I’ve recently switched back from Brackets to Atom and there’s one feature I’m sorely missing is an autocomplete suggestion feature for HEX color values in my current document (mostly for writing CSS). When I declare a color-related property in CSS (alternatively when I write the #-sign in a CSS document), I would like to get the list of autocomplete suggestions containing all the colors I have used in my current document. I’m talking about ‘pure’ CSS, i.e. when I’m not using a preprocessor.

I have not found any package that does this. I have tried pigments, but that doesn’t seem to do what I want it to. Is there a package that will add this functionality? Or do I just need to configure pigments in a certain way?