I touched on this briefly in my article about the difficulty inherent in finding natural-looking reds, but allow me to recap one very important point relevant to why realistic red and blonde shades are BOTH so difficult to find:
- Because these are very rare hair types in nature, it is difficult to duplicate them in salons, and by extension, extremely difficult for wig manufacturers to convincingly duplicate them in their factories. There is a danger zone that exists called the "Uncanny Valley" -- if something artificial gets super-duper close to approximating the real thing only to fall a little short, the closer it got to the genuine article, the more uncomfortable we actually feel about it. In short, if the color isn't ABSOLUTELY PERFECT, then it looks completely fake and we hate it. In rare hair colors like this, it becomes a knife-edge, all-or-nothing game betwixt the manufacturers and the consumers. Most manufacturers opt out rather than risk losing money on a mass-produced color that nobody likes.
To avoid the quagmire of the Uncanny Valley, most manufacturers veer away from colors that look too natural because, paradoxically, they look very "wiggy" to most consumers.
Instead, what you will mostly find (especially in the reds and blondes) are heavily highlighted colors that look like they've been dyed by a professional colorist. The reds are EXTREMELY red or copper. The blondes have INTENSE highlights near the face.
These combinations are not natural-looking -- and they're that way by design. This is also why the most popular blondes tend to have very dark roots. Not only are they easier for most women to pull off, but they avoid the Uncanny Valley immediately, because they don't attempt to look like a natural color that grew out of someone's head; the rooting completely negates that possibility in a split second!