PHILADELPHIA — Hillary Clinton’s campaign is pulling its television advertisements from Colorado, at least temporarily, after building a sizable and durable lead in the traditional battleground state.The decision could reflect increasing confidence about Clinton’s chances to capture Colorado’s nine electoral votes in the fall. But a Clinton campaign official, granted anonymity to discuss the campaign's internal operations, stressed the campaign's advertising strategy against Donald Trump will change constantly over the next three months.Colorado was part of the Clinton campaign’s initial, general-election advertising campaign, which began in mid-June and cost at least $22 million.