Re: solarized

[Yuri Khan <yuri.v.khan@gmail.com>]

On Tue, 15 Sep 2020 at 15:44, Protesilaos Stavrou <info@protesilaos.com> wrote:

> Solarized fails on the accessibility front (not its designer's fault, as
> that was not its goal).  Many colour combinations are well below the
> minimum 4.5:1 threshold.  The following table shows the relative
> luminance of all colours of the palette compared with the four base
> background values (table's image with colour previews also attached).

A color theme does not have to provide 4.5:1 contrast for each-to-each
color combination. Only for those that are actually used to display
text.

The important ones are:

* base dark colors against base lightest color
* base light colors against base darkest color
* accent colors against base lightest and base darkest colors

Slightly less important:

* base dark colors against base second-lightest color
* base light colors against base second-darkest color
* accent colors against base second-lightest and second-darkest

> | SOLARIZED | HEX     | #002b36 | #073642 | #eee8d5 | #fdf6e3 |
> |-----------+---------+---------+---------+---------+---------|
> | base03    | #002b36 |         |         |   12.25 |   13.92 |
> | base02    | #073642 |         |         |   10.61 |   12.05 |
> | base01    | #586e75 |         |         |    4.39 |    4.99 |
> | base00    | #657b83 |         |         |    3.64 |    4.13 |
> | base0     | #839496 |    4.75 |    4.11 |         |         |
> | base1     | #93a1a1 |    5.61 |    4.86 |         |         |
> | base2     | #eee8d5 |   12.25 |   10.61 |         |         |
> | base3     | #fdf6e3 |   13.92 |   12.05 |         |         |
> | yellow    | #b58900 |    4.68 |    4.05 |    2.62 |    2.98 |
> | orange    | #cb4b16 |    3.26 |    2.82 |    3.76 |    4.27 |
> | red       | #dc322f |    3.25 |    2.81 |    3.77 |    4.29 |
> | magenta   | #d33682 |    3.30 |    2.86 |    3.71 |    4.21 |
> | violet    | #6c71c4 |    3.43 |    2.97 |    3.57 |    4.06 |
> | blue      | #268bd2 |    4.08 |    3.53 |    3.00 |    3.41 |
> | cyan      | #2aa198 |    4.75 |    4.12 |    2.58 |    2.93 |
> | green     | #859900 |    4.69 |    4.06 |    2.62 |    2.97 |

Also, Solarized picked a design decision of using the same accent
colors against dark and light backgrounds. This makes it hard to
satisfy the 4.5:1 requirement, because if accent is at least 4.5:1 to
darkest and lightest is at least 4.5:1 to accent, then lightest must
be at least 20.25:1 to darkest, and the chosen Solarized lightest and
darkest do not satisfy that. So, within the given limitations,
Solarized does well enough.

(Disclosure: Personally, I do not like or use Solarized, because of
its heavy tinting of the light background to yellow. Light backgrounds
are supposed to resemble paper, and yellowish paper looks cheap and/or
old to me.)