As for why Pale Ale is called, it’s actually because it USES a lighter roast malt. In a typical pale ale, malt and hops are well balanced. Simply put, the sweetness of malt and the bitterness of hops are well combined. And pale ale’s hops, though clearly expressed, can be very mild.
English India Pale Ale (IPA)
The IPA was originally made with a large number of hops, designed to ensure that beer does not rot quickly on long voyages from England to India, because the hops are so preservative that they keep the beer fresh. IPA used to be, and still is, British hops (not necessarily now), and tends to reflect the aroma of soil, wood and spices.