Tickled pink

This expression derives from tickled meaning pleased or delighted, which dates from the 16th century. Shakespeare used the expression in Coriolanus Act I, Scene I, “tickled with good success”. Tickled pink, however, is a much newer expression dating from the late 19th/early 20th century, possibly from association with in the pink meaning in good condition or health, but more likely from the pink or reddish flush that some people give off when they are happy or excited.