Complex sentence: The trigger for this change was most likely around 540 BCE when imported red figure painting appeared with its new representation possibilities, which obviously inspired him to use richer ornamentation, transferring it, as far as possible, to his black figure painting.
Split into simpler sentences: The trigger for this change was most likely around 540 BCE. He took over from the young red figure painters richer ornamentation and transferred it, as far as possible, to his black figure painting.