Hans Riegel, owner of Haribo, the maker of the rainbow-colored, fruit-flavored, teddy bear-shaped candy known as gummi bears, died on Tuesday, at the age of 90. 

Riegel, who underwent successful surgery this year to remove a benign brain tumor and was "on the way to recovery" died of heart failure. Riegel died in Bonn, Germany where the company's based, the Associated Press reported. 

Riegel transformed his family-owned company from a local candy maker with 30 workers into an international brand with 6,000 employees around the world and annual sales of about $2.7 billion. Riegel had a net worth of $4.2 billion, according to Bloomberg Billionaires Index. 

Riegel's father, also named Hans, founded Haribo in 1920. In 1922, his father invented the "dancing bear," a small bear made out of fruit gum that later became known as the "gold bear."

After the founder's death in 1945, Riegel and his younger brother, Paul, set out to rebuild the family business, after World War II. According to the New York Times, Paul, who died in 2009, was responsible for production while Hans oversaw sales and marketing. Riegel reportedly took his inspiration from children's magazines and comics.

"I love children," Riegel said, according to the AP. "They are my customers. I have to be informed about what they want to nibble, what they think, what language they speak."

The little bears, which come in five colors and flavors, were popular with Germans and lead Riegel to later expand abroad. The sugary treat was introduced to Britain, Sweden and Austria in the 1970s and later the United States in 1982, setting up Haribo of America in Baltimore. Haribo also makes a chewable soft candy called Maoams, as well as marshmallow candies, and licorice whips. 

"We owe Dr Hans Riegel a debt of thanks, as he had the foresight to change the company's direction in time to ensure its successful future and steady growth," Haribo of America wrote on its page. "All of us are now called upon to continue his lifetime's work together."

Riegel was born on March 10, 1923. He served as a solider in World War II and returned to Germany in 1946 after spending time as a prisoner of war, according to Spiegel magazine. He studied economics at the University of Bonn and completed a doctorate in 1951 on the global sugar industry. 

Riegel was awarded Germany's highest honor, The Federal Cross of Merit, in 1994. It was recognition for his business career and his commitment to social issues, such as encouraging the training of talented young people, and sports. According to the AP, Riegel was a passionate player and promoter of badminton.