Just to give an overview of how this will be implemented:

Basically, we'll be adding the CSSnext library to our build process.

CSSnext will allow us to use new CSS features (such as css-custom-properties)
and it will then compile these features into regular CSS that is compatible with older browsers.

This color will be defined once in a css-custom-property (let's just call it variable) and used across the CSS as needed.

The advantage of this approach over using a CSS pre-processor like SASS or LESS is that CSSnext implements
features that are based on current and future web-standards, so eventually, all the features we'll use today will
be considered standard CSS.

thanks for the update, @Jdrewniak!

Change 267884 had a related patch set uploaded (by Jdrewniak):

• Adding postCSS preprocessor - changing the link color - changing bookshelf color

https://gerrit.wikimedia.org/r/267884

few tries to get the colors the way we want, thanks @Jdrewniak for sharing!

We've decided to use the new blue from the UI standardization effort: #165c91
https://phabricator.wikimedia.org/diffusion/WMUI/
as #347BFF seemed a bit too bright for text links.

Thanks, @Jdrewniak, is it ready to be merged into Master?

@debt This patch required some more changes today, so it's still in review, but I think all the issues have been worked out.

Cool! Can you give us a screen shot to view while the code is being reviewed?

Change 267884 merged by jenkins-bot:
Adding postCSS & changing blue. - Adds the postCSS CSSNext plugin. - Moves the CSSnext files into a dev subfolder. - changes the link color to ##165c91 to align with the UI Standardization effort: https://phabricator.wikimedia.org/diffusion/WMUI/ - chan

https://gerrit.wikimedia.org/r/267884