Symbols of colors used in Portugal for transport

[Mark E. Shoulson via Unicode]

On 4/29/19 3:34 PM, Doug Ewell via Unicode wrote:
> Hans Åberg wrote:
>   
>> The guy who made the artwork for Heroes is completely color-blind,
>> seeing only in a grayscale, so they agreed he coded the colors in
>> black and white, and then that was replaced with colors.
>   
> Did he use this particular scheme? That is something I would expect to
> see on the scheme's web site, and would probably be good evidence for a
> proposal.

And what about existing schemes, such as have already been in use even 
by the esteemed company present on this very list, and in several fonts, 
for the same purpose?  See 
https://en.wikipedia.org/wiki/Hatching_(heraldry)

> I do see several awards related to the concept, but few examples where
> this scheme is actually in use, especially in plain text.
>   
> I'm not opposed to this type of symbol, but I like to think the classic
> rule about "established, not ephemeral" would still apply.

Indeed.

If there were encoded mere color patches (like, say, colored circles, 
possibly in the U+1F534 range or something; just musing here), would 
those already count as encoding these sorts of things, as 
black-and-white font designers would be likely to interpret them in some 
readable fashion, perhaps with hatching. Is it better to have the color 
be canonical and the hatched design a matter of design, or have a set of 
hatched circles with fixed hatching?

~mark