Low text contrast and no visual cues for links within body text in admin UI

[Thibaud Colas]

The Django admin’s light theme uses a light blue for links within text, with no other distinction of what is a link. This is problematic for two reasons:

• The current shade of blue, #447e9b, doesn’t have enough contrast against the white body background.
• For people with color blindness, there is no visual cue that a link is a link.

For those reasons, I would recommend:

• Changing the link color of --link-fg. My recommendation would be to use an ever-so-slightly darker #437c98 (1% less lightness in HSL representation)

- Introduce an underline for all links within body text, so they can be identified unambiguously.

[William Claassen]

A pull request has been added: ​PR. This includes:

• Changing the default colour to a slightly darkened in light mode (-1% lightness in HSL colour space) as requested
• Adding underline on hover for all default links (add/create links, breadcrumbs...) to make links easier to identify

[Mariusz Felisiak]

The new color have enough contrast when the background is white. Unfortunately --link-fg is also used with yellow (#ffffcc) and gray backgrounds (#f8f8f8). We should make it even darker to meet AA standards, e.g. #417893.