Legend has it that the earliest Irish ales were most likely brewed in monasteries and were red in colour. Today, Irish Red Ales are amber to dark reddish copper and usually have a deep red tint to them. They exhibit a toasted malt flavour with a medium sweet caramel flavour. These maltcentric beers are low to medium in hop flavour and bitterness due to poor hop growing conditions and expensive English tarrifs. Like Irish Stouts, they have a dry finish from roasted grains. Designed to be an everyday beer, Irish Red Ales typically have an ABV between 4-6.5% and IBUs from 17-28.
Summary from www.beertutor.com