Change Nim's colour to better match the logo

[ghost]

This PR changes Nim language's colour to better match the logo - from #37775b to #ffdf00

Description

For a long time I wondered why Nim has the green colour on GitHub, and today I decided to dig deeper in it. Turns out Nim was made green by the initial commit which added colours - c3d6fc5 and was never changed after that.
With this PR I want to make the colour more consistent with the logo and branding (most of it is the goldish yellow)

Checklist:

• I am changing the color associated with a language
  • I have obtained agreement from the wider language community on this color change.
    • I opened a forum thread to spread the info about that PR: https://forum.nim-lang.org/t/6350, shared this PR in IRC, the Telegram channel, the Discord server
    • Official assets - https://github.com/nim-lang/assets

[ghost]

Alternatives to try: #ffe953

[ghost]

About feedback - is it fine if people just do thumbs up/down to this PR? I've spread this PR in all places in the community I know about, and some well-known Nim developers (including Nim's creator :P) already upvoted this PR. Of course we still need to wait a few more days so more people can vote on this change.

And now I need to find a good goldish-like colour for Nim, because these two seem to be too close to other ones

[ghost]

Found a working colour - #FFDF00, would it be fine?

[ThomasTJdev]

The latest proposed color in is too white'ish for me to read. It fades into the standard white background at Github and makes it hard for the eyes.

I would go for a darker yellow.

Current proposal in the PR (#ffdf00):

Color inside the Nim crown ( #f3d400):

Darker yellow (#c9b31a):

[ghost]

@ThomasTJdev it's not for the code, it's for the color in language % of repos and in short view for repos (where there's a color near the language name)
See:

And both #f3d400 and #c9b31a fail the color proximity test

After this PR (with the current colour):

[ghost]

This is how Nim will look after this PR (JS seems to have one of the most similar colors to golden yellow):

[ThomasTJdev]

This is how Nim will look after this PR (JS seems to have one of the most similar colors to golden yellow):

Ahh - my mistake. Then I'm all in for your proposal - a 👍 is added.

[pchaigno]

LGTM! Thanks for your pull request and for taking the time to check with the community!

[lildude]

I'm going to need to revert this as it seems the colour proximity test didn't pick up a problem, but it is now on master:

  1) Failure:
TestColorProximity#test_color_proximity [/home/runner/work/linguist/linguist/test/test_color_proximity.rb:21]:
The following 1 languages have failing color thresholds. Please modify the hex color.
- Nim (#ffdf00) is too close to ["FFEC25", "ffdf00"]

We're going to need tweaking to resolve this.

[lildude]

I've now worked out why the passed before: Dafny got the #FFEC25 colour before Nim's change so it was merged first.