Enhance github theme for accessibility (minimum contrast)

[oddhack]

Is your enhancement request related to a problem? Please describe.

The github theme has a number of color / background choices that raise accessibility issues in tools like ANDI - specifically, many colors in C language highlighting (and probably many other languages) fail the 4.5:1 contrast ratio requirement.

Describe the solution you'd like Update github theme CSS packaged with rouge to satisfy ANDI requirements. This means shifting these colors a bit to increase contrast relative to the grayish background of the theme, following ANDI recommendations.

Additional context Before capturing screenshots etc., I'd like to ask if this is a change that the project is willing to accept? If so I'll provide more details, and propose a PR if the themeing system is straightforward to modify. If not I'll deal with this by a CSS override in our project. Accessibility issues seem of general use. But I don't understand the full context of where the github theme originated or how important compatibility between the origin, rouge, and other source highlighters is to you.

Note I had initially thought this was just affecting a couple of the CSS classes in the theme, but the contrast issue is more pervasive. I'm not sure how the theme stylesheets are being generated - are they in something like compass .scss markup? That would be the least painful point to fix them since the colors are presumably defined once and used many times.

[stale[bot]]

This issue has been automatically marked as stale because it has not had any activity for more than a year. It will be closed if no additional activity occurs within the next 14 days. If you would like this issue to remain open, please reply and let us know if the issue is still reproducible.

[oddhack]

I'd like this to remain open. We have worked around it by CSS overrides but that's not a great long-term solution (and was very tedious to figure out what the many overrides were), and doesn't benefit other users.

[Bukama]

It's the same problem for the rogue default theme used by website (e.g. the JUnit User Guide).

[jneen]

You can actually create your own theme without CSS overrides, fwiw.

[jneen]

...or use one of a large number of pygments stylesheets https://stylishthemes.github.io/Syntax-Themes/pygments/