Cationic [n]helicenes ( n = 4,5,6), based on bridged triarylmethylium skeletons, are highly stable carbenium ions, which can be stored as carbocations under air. Most of them are inert even in strongly alkaline aqueous solutions. These colorful dyes can be tuned electronically by changing their intrarim heteroatoms or by diverse regioselective additions of substituents (auxochromes). Fluorescence in the red to NIR is also afforded with moderate to excellent quantum yields and lifetimes up to 10 ns and above. Many applications, detailed herein, have been reported, thanks to their simple and flexible synthesis that yields helicenes with (very) high configurational and chemical stability and tailored optical and redox properties.