Not sure why R's if_else() fails! R type system misunderstanding? Misunderstanding of NA?

The following is me trying to convert my 2019 and 2020 flickr photos’ average colour to one of 657 R standard colours instead of the possible 256xx256x256 = 16777216 colours.
It’s probably my misunderstanding and a type issue R but not sure why the following never executes the if portion and always executes the else portion (full code is in my repo over on github):
```
if_else(synth_75imaveragecolour == "<NA>", as.hexmode(0), getnumericColour(synth_plotrixcolour)))
```
I also tried is.na() and == "" and neither of those worked
It’s probably my misunderstanding of the R type system!
I think I can diagnose this further by writing a loop (!) and printing out the values and the types or by using a 2 row tibble to debug further.