bug#47133: 28.0.50; Library chart: colors sometimes appear, sometimes not

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Thu, 18 Mar 2021 07:47:41 +0100
> Cc: 47133@debbugs.gnu.org
> 
> Perhaps it's a case of what display that's active when you're loading
> chart.el?  What's the value of `chart-face-list' when you don't see any
> colours?  It's defined as:
> 
> (defvar chart-face-list
>   (if (display-color-p)
>       ...
> 
> so if the display in question doesn't support colours when loading,
> you'll get no colours on any display, I think.

Which displays nowadays don't support colors in Emacs?  Does anyone
still use such displays?