Here's why:
* Strawberry blond is a light red-blond mix: It's essentially blond hair with a reddish or golden undertone.
* Lightening removes pigment: Any hair lightening process (bleach, highlights, etc.) works by removing pigment from the hair shaft.
* Removing red tones: As the hair lightens, the reddish tones inherent in strawberry blond would be reduced, leaving a more pure blond color.
* How light it goes depends: The final color would depend on the degree of lightening. It could range from a light golden blond to a very pale, almost platinum blond.
So, in essence, lightening strawberry blond hair is essentially removing the "strawberry" to leave just the "blond."