One of the lesser-known advantages of wxWidgets compared to many other libraries is that, using its API, you can centre a window on the screen and set its colour to grey without having to Americanise your programme. But, as natural as this behaviour is, and in spite of agreeing to wxWidgets licence (the very spelling of which should have been a sufficient hint), some users still expressed their surprise in their dialogue with us and refused our advice to accept using this flavour of the API. And so, to accommodate them, wxWidgets has traditionally provided alternatives such as Center() method, wxColor class and wxGRAY constant.
Admittedly, in practice this has been sufficient to avoid any problems for a long time while still remaining true to wxWidgets historically British roots. However, in addition to being British, wxWidgets was always mostly a European effort and, besides, knowing that it was actually born in Edinburgh, it might well end being exclusively European and not British at all in the near future (but don't worry, even if the worst happens, we plan to continue supporting British spelling for at least two more release cycles, in accordance with the general backwards compatibility policy). Considering this, it seems especially strange to have alternative American versions of the spelling, but no attention being paid to the other European languages.
And now, after releasing 3.1.0, it's finally time to do something about it as, clearly, there are few unresolved issues of comparable importance left. To begin with, I obviously had to add wxCouleur class which should undoubtedly help with wxWidgets adoption in francophone countries. But adding just the French variant would certainly be undiplomatic, so another pull request adds, in the grand European tradition of Franco-German alliance, wxFarbe, and both of them will be merged together to avoid any questions of precedence. Further, France and Germany notwithstanding, I certainly don't plan to discriminate against other countries but, in the usual spirit of Open Source, additions of wxColore, wxFarve, wxKleur etc will have to wait until the appropriate patches are submitted (luckily for them, Spanish users can, in the meanwhile, already reuse the American variant, just as they already do with many other words, e.g. burrito, for the classic American food).
Of course, nothing is ever as simple as planned and, while working on this, I quickly realized that Greek might present some practical difficulties as UTF-8 support is still, even in 2016, not perfect on some of the legacy platforms supported by wxWidgets, but it would be difficult to use wxΧρώμα without it. A compromise solution that we're currently discussing would be to introduce a wxChroma class right now and deprecate it by the time 3.2 is released as Unicode support should really be widely available everywhere by then (3.2 release is currently planned for the early 2030-ies).
I do hope you will enjoy these changes, but, let's be honest, this is just the beginning and we clearly still have a lot of work to do in this area. Fully supporting colour internationalization is important, but it's just the first step and we plan to go much further. Just imagine to be able to open a wxFenêtre and choose a wxStylo for drawing on it and then, perhaps if you live in Switzerland, create a wxKnopf as its child. The possibilities are endless! Unfortunately, the same can't be said about our resources, so we count on your help to make wxWidgets the best internationalized library of all time -- and we're looking forward to your contributions!