Ladd-Franklin developed her own theory of colour vision while working in Germany and in 1892 she visited England and presented it to an International Congress of Psychology in London.
Ladd-Franklin bumuo ng kanyang sariling kuru-kuro ng kulay paningin habang nagtatrabaho sa Alemanya sa 1892 at siya bumisita sa Inglatera at ipinapahayag ito sa isang International Congress ng Psychology sa London.