Yaru: Menubar items should use a darker text color

[godlyranchdressing]

A new $headerbar_text_color should be used instead of the standard headerbar text color.

[clobrano]

@godlyranchdressing could you provide a picture of such a menubar item?

[godlyranchdressing]

I don't know how we're going to handle the text colors till I sift through the new stuff posted by Canonical and get some ideas though. The checkboxes might get overridden when I'm updating them to match Canonical's, so maybe this will need to be put on hold till that stuff is organized.

(Better inactive text colors here from Mads' mockup) ---

A transition would make the text color change more obvious.

[madsrh]

A quick contrast test with the Canonical colors:

[godlyranchdressing]

@madsrh is that title/subtitle/caption or active/disabled/backdrop?

[madsrh]

@godlyranchdressing it's a bit unclear here and also page 13 in Colour in the toolkit