Colorize multi-triplet dot graphs

[dg0yt]

Just 8361878
Depends on (for now, includes) #1369 and #1370.

Example:

vcpkg depend-info proj:arm64-linux proj tiff[core] --triplet x64-linux-dynamic --dot | dot -Tpng -oimg.png && xdg-open img.png

Output:

[autoantwort]

So non default triplet -> red; default triplet -> black; host triplet -> gray?
Maybe use blue instead of red, red looks like an error 😅

[dg0yt]

Maybe use blue instead of red, red looks like an error 😅

Done.
(And there is room for "error", such as "unsupported".)

[BillyONeal]

I'm a bit concerned that grey is a bit too close to the background color; I'm worried about accessibility requirements, that sort of thing.

How about DimGray, HTML color #696969 ?
or perhaps DarkSlateGray, HTML color #2F4F4F ?

[BillyONeal]

I am happy with the code here pending quibbles over the specific colors and an Ok from our PM team /cc @AugP

[BillyONeal]

I'm a bit concerned that grey is a bit too close to the background color; I'm worried about accessibility requirements, that sort of thing.

How about DimGray, HTML color #696969 ? or perhaps DarkSlateGray, HTML color #2F4F4F ?

I note that on https://graphviz.org/doc/info/colors.html they use black text on gray and white text on dimgray and darkslategray suggesting that the latter two are more appropriate for contrast against a white background

[AugP]

I have no objections to this, assuming it passes our accessibility compliance requirements. @BillyONeal can you confirm if this conforms to our accessibility requirements?

[dg0yt]

After some playing with different candidates, I switched to gray51. This is the lightest (=most distant from black) gray which is still label with white text (=distant enough from white) on https://graphviz.org/doc/info/colors.html.

[dg0yt]

FTR all default native requests remain B/W.

[BillyONeal]

Thanks :)