Lucille Ball was born a brunette, but dyed her hair blond for
her early days in Hollywood. When she was about to make her
first film for MGM in 1942 (“Du Barry Was a Lady”), Sydney
Guilaroff, the studio’s chief hair stylist, made a discovery
that would change her for the rest of her life. “The hair is
brown,” he said after looking at the 31-year-old rising star,
“but the soul is on fire.” So he dyed Ball’s hair Tango Red (a
shade between carrot and strawberry), which it remained until
she died.
Incidentally, Betty
Boop's original hair color was red.