Formula One's ruling body, the FIA, has confirmed drivers will be unable to change their helmet designs during the season.
Under the new rule, which has now been added to the 2015 sporting regulations, drivers will only be able to make small tweaks to the helmet livery, with the FIA saying the design must be "substantially" the same throughout the course of the season.
The FIA insists the new regulation is aimed at making it easier for the fans to distinguish the drivers.
"In order for drivers to be easily distinguished from one another whilst they are on the track, the crash helmet of each driver must be presented in substantially the same livery at every Event during a Championship season," said the new rule.
Four-time world champion Sebastian Vettel, who has changed his colours no fewer than 60 times since his F1 debut, called the move a "joke".
Race promoters wanted change
The introduction of the rule has been widely controversial, but Mercedes team chief Wolff thinks the timing may simply have been unfortunate, given the stalemate on other matters like engine rules and cost-cutting.
"This detail coming out of the F1 Commission made us look like we have nothing else to do than discuss driver helmets," he told Sky.
"As a matter of fact, the promoters are struggling a bit to promote their grands prix."
Wolff said that while die-hard F1 fans are able to keep up-to-date with the drivers' helmet changes, less regular viewers do not.
He said driver recognition has therefore become an "important" issue.
"So either you put big numbers on the car, which we didn't like, or you make the driver more recognisable with the helmet," the Austrian said.
"If the promoter thinks that it will help him sell tickets, I think that's a good argument."