I have blond hair.
 blonde (female), or fair hair, is a hair color characterized by low levels of the dark pigment 
And is grey hair when it loses all pigment?
color can be from the very pale blond (caused by a patchy, scarce distribution of pigment) to reddish "strawberry" blond or golden-brownish
And is blond the most common hair color?
Interestingly,Red hair (or ginger hair) occurs naturally in 1–2% of the human. 
What about blond hair?
Old French "blund, blont", meaning "a colour midway between golden and light chestnut". It gradually eclipsed the native term "fair", of same meaning, from Old English "fæġer", causing "fair" later to become a general term for "light complexioned". This earlier use of "fair" survives in the proper name Fairfax, from Old English "fæġer-feahs" meaning "blond hair".
The word "blond" has two possible origins. Some linguists say it
Blond
Blond or fair hair is a hair color characterized by low levels of the dark pigment eumelanin. The resultant visible hue depends on various factors, but always has some yellowish color. The color can be from the very pale blond (caused by a patchy, scarce distribution of pigment) to reddish "strawberry" blond or golden-brownish ("sandy") blond colors (the latter with more eumelanin). Because hair color tends to darken with age, natural blond hair is generally rare in adulthood. Naturally