Answer: When it's not purple of course!
|Wild 'White' Violet|
A very different plant, especially when seen growing in abundance.
I admit I'm not very astute when it comes to identifying plant life and tend to forgive other peoples' mistakes since I appreciate I make so many myself. That said I'm continually surprised when I hear people refer to celandine as buttercup or these little chaps (grape hyacinths) as bluebells: