The United States launches on Tuesday a new $100 bill that comes with, for the iconic greenback, a new touch of color, as well as special features to foil counterfeiters.

In its first remake since 1996, the $100 banknote, which takes a key role in cash transactions for everyone from small traders to big drug traffickers worldwide, sports the traditional portrait of American Revolutionary War statesman Benjamin Franklin on the front.

On the back, too, it depicts Philadelphia's Independence Hall, where the Declaration of Independence was adopted on July 4, 1776.

But it adds a yellowish "100" in one corner and, next to Franklin, a tan quill and bronze-colored inkwell that holds inside it the Philadelphia Liberty Bell in changing colors from darker brown to green, depending on the angle the note is held.

Cutting vertically through the middle of the banknote is a blue security ribbon that shows numerous small Liberty Bells and 100s printed in darker blue, which appear to move as the note is shifted.

While the feature appears like a hologram, the 100s and bells are actually microscopic in size and are enlarged by millions of micro-lenses printed on the note which make the figures appear to move, said Sonja Danburg, program manager in charge of currency education at the Federal Reserve.

The new design comes primarily to fight the increasing sophistication of counterfeiters, Danburg told AFP.

"It's our most global banknote. Between a half and two-thirds of them are circulating outside of the United States, and it's also the most counterfeited of US denominations outside of the United States," she said.

"We want to stay ahead of counterfeiting threats, we want to protect the public."

Danburg said that counterfeiters, from small-time printers to state-sponsored crooks, remain a challenge though their production is small in contrast to the total amount of greenbacks in global circulation -- about $80 million last year, compared with about $1 trillion in US notes circulating.

The new $100 banknote, printed on the traditional cotton and linen paper with green and black ink, has other foils for copiers.

For instance, the design includes showing the back of Independence Hall, rather than the building's front as before, so copiers cannot just use their old printing plates.

The government has printed 3.5 billion of the new banknotes, which will hit the streets in the United States on Tuesday.

It will take some days before banks that receive them from the Federal Reserve ship them to branches and counterparts around the world.

But the Federal Reserve wants to make sure users around the world recognize the new design as valid and do not reject them.

"People are relying on it not only as a medium of exchange for business or consumer transactions. It also offers a store of value. We want to make sure that everybody who is relying on US currency maintains that faith and confidence in it."

With some $900 billion of the old $100 notes still out on the market, Danburg stressed they will be honored as long as they circulate.

"It's US government policy that all our designs remain legal tender. So you don't have to rush out and trade in the older ones," she said.