need to increase contrast in all emacs faces for legibility

need to increase contrast in all emacs faces for legibility

[Samuel Wales]

at night, i need much more contrast in my emacs faces in order to
increase legibility.

during the day i want the same faces i currently have.

is it possible to programmatically increase foreground contrast
against their background in all faces?

i already have the background black or close to it.

i have heard that in practice, it is not a question of just increasing
brightness.  there is an accessibility website that can calculate it
but i don't know the url.

but even if nobody knows the theory of contrast perception, or
whatever applies here, even just increasing foreground brightness of
all faces would probably increase legibility.

thanks.

Re: need to increase contrast in all emacs faces for legibility

[Marco]

Hello,

> is it possible to programmatically increase foreground contrast
> against their background in all faces?

While I can't answer your question, which is an interesting one (don't
think it's org related, though), I just wanted to ask: can't you just
adjust the temperature of your display with a tool such as redshift
(for linux) or f.lux (windows)?

Re: need to increase contrast in all emacs faces for legibility

[Pankaj Jangid]

> is it possible to programmatically increase foreground contrast
> against their background in all faces?


For shr (the built-in browser), there is something. But in general I am
not aware if there is something related to this.

shr-color-visible-distance-min, shr-color-visible-luminance-min

These two variables are used for shr.

Re: need to increase contrast in all emacs faces for legibility

[wry]

On 12/10, Samuel Wales wrote:
>at night, i need much more contrast in my emacs faces in order to
>increase legibility.

This is counterintuitive, normally you need to increase contrast
during the day and decrease contrast (and lower brightness) at night
to prevent eye strain. Unless you're using an E Ink display or
something crazy, decreased ambient light should not affect legibility
(pixels are backlit), only eye strain.

>is it possible to programmatically increase foreground contrast
>against their background in all faces?

>i already have the background black or close to it.

Studies have suggested that light text on dark background is less
legible than dark text on light background, so you could change
that. Anecdotally this is true for me in Emacs and on the web, but the
decreased eye strain at night is worth the tradeoff of using a dark
background.

I doubt Emacs has this contrast functionality built in. You can always
change themes (M-x customize-themes). A quick Google of "Emacs high
contrast themes" yields at least one theme you could try.

You can even manually modify themes. Just go to the Elisp file and
play around with the theme definition. Use Gimp or Google "HTML color
picker" to find new colors to replace whichever color you're not
satisfied with.

If you're actually trying to reduce eye strain at night, there are
several tools at your disposal.

- Redshift has already been mentioned; I consider my computer
  basically unusable at night without it
- Decrease display brightness using software
  (e.g. https://github.com/haikarainen/light )
- Change brightness or color settings at the hardware level (by
  clicking buttons on your monitor)
- Add more ambient light around your monitor
- Computer blue-light filtering glasses (I don't know if they're effective or not)

Need to increase contrast in all emacs faces for legibility

[Bruce Russell]

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Protesilaos Stavrou has uploaded two (light and dark) “accessibility” themes with “consistent minimum contrast ratio between background and foreground values of 7:1 or higher" to Melpa. See https://www.youtube.com/watch?v=zofd0O12XWE <https://www.youtube.com/watch?v=zofd0O12XWE>. The source code is on GitLab at https://gitlab.com/protesilaos/modus-themes <https://gitlab.com/protesilaos/modus-themes>.

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