Shedding 'light' on cigarette pack design: colour differences in product perceptions, use and exposure following the US descriptor ban.

Misperceptions about nicotine and tar exist years after rebranding Marlboro Lights as Marlboro Gold. Biological results support that Gold smokers do not have lower toxicant exposure. The US should consider comprehensive packaging or product design regulations to properly inform smokers of product risks.Trial registeration numberNCT02301351.