The first Nixie clock that I built featured inexpensive Russian ИН-12Б end view tubes which have an inverted '2' for the '5'. This was something that I found rather displeasing about their design.
NB The LED backlight colour is programmable, I usually have it on a random setting.
I was delighted when PV Electronics began to stock German AEG ZM 1100 orange coated tubes. Although very slightly smaller than the ИН-12Б, they have exactly the same pin layout and spacing. Crucially, they have a much more pleasing design of numeral and the orange coating improves daylight visibility (but can also easily be removed).
It was a simple matter to swap them over, and I'm very happy with the result.