Update Racket color based on new logo

[pmaddams]

No description provided.

[lildude]

Unfortunately this PR can't be merged yet as it's not passing CI because the colour you've chosen is too similar to that used by another language. You're going to need to experiment with the colour until you find one that didn't conflict. I understand this may be quite a challenge.

[pchaigno]

If you're going to change the threshold, please do some thorough tests and justify why this is needed.

[lildude]

I'm also gonna have to stop you now. Increasing the threshold to satisfy your colour selection is not the best approach (it's also the wrong way round) as you can see from the ever increasing number of conflicts being reported in the subsequent tests.

Take a look at the colours reported in the initial failure:

#3e5ba9 (your chosen colour)
#375eab
#4F5D95
#3e5ba9

As you can see, they're all very very close and not easily distinguishable.

You need to adjust your chosen colour, not the threshold.

[lildude]

Apologies for the failed commits. Because I don't have a development machine right now, I am making changes on my phone. Several points:

No problems, though you'll find it much easier to test this stuff on an actual computer 😉

The chosen color is the same one used in Racket's logo. If you look at the raw SVG file you will see:
<path id="blue-piece" fill="#3E5BA9" ...

I saw that.

I understand the color is somewhat similar to Go and PHP. However, they are clearly not identical, and blue is a very popular color. There is little danger that someone will confuse Racket with Go or Racket with PHP.

Indeed. Blue is incredibly popular and it is for this reason we've had to implement this threshold test and it's why, if you're going to want a shade of blue, you're going to have to pick another.

#3e5ba9 (your chosen colour) and #4F5D95 are so remarkably close that it's almost impossible to tell the two apart when they're side-by-side as they could be in the language statistics bar (I know, highly unlikely, but remotely possible):

#3e5ba9 (your chosen colour) and #375eab are a little more distinguishable, but not easily:

(I cunningly changed the proportions between the two screenshots to make guessing the breakpoint harder 😉)

Why not keep the current colour #22228f? It's not that far off the colour you're trying to set it to
and many other languages stick with their original choice so as not to confuse their users.

Or how about a variant of the red (#9F1D20)? This currently conflicts with only one other language so a slight tweak to the hue or something should get past this. A quick little testing shows #9F1D26 is close enough to the red in the logo to be almost indistinguishable and without any conflicts. You could try a similar tweak with your blue if you absolutely want a blue, though this will much more of a laborious task due to the high number of blues already in use.

The threshold should be decreased anyway because with an increasing number of languages on GitHub, conflicts are bound to occur. It is like filling up a hash table; you must expect collisions. Having done a search of the possible values, 0.01 is the only one that works without going to a higher number of decimal places.

Indeed there are an increasing number of languages and conflicts do occur, however we (the Linguist community) can't unilaterally decide on lowering the threshold without a full and comprehensive analysis of the languages on GitHub and how such a change would impact the overall appearance of the language statistics bar on GitHub.com, especially when there are a lot of unused, and significantly more unique, colours still available.

Not every language has a colour directly associated with their logo or website colours as a deliberate choice to make it more unique on GitHub, that's also an option.