The advent of the Dreadnought Battleships not only revolutionised the Battleship types but also all of the support ships that had been previously built. At 17-19 knots the pre-Dreadnoughts had only required cruisers to make 22-24 knots to give them enough of a speed margin to escort and act as scouts to the large fleet units. The last cruiser class for the Incan Navy had been the very large armoured cruisers of the Belem class. At 24 knots those ships were now only 2 knots faster than the new Collasuyu class dreadnoughts. Not enough of a margin to be useful, also having triple expansion engines the Belem's were unable to maintain the constant speed of the new turbine powered ships. What was needed was a new type of scout / anti-torpedoboat destroyer. To give enough of a margin of speed over the dreadnoughts, a speed of 28 knots was specified. Armour would have to be reduced to a two inch belt and one inch deck. Enough to give cover for the 4"-5" guns that they might face from destroyer type ships (and even some older light cruisers). To counter these ships the Colorado's were armed with eight 6" single guns, with one fore and aft and three down each side. A pair of 18" torpedoes (on each side), a single 100mm gun (later replaced with an AA gun) and three 3 pounder close in weapons.
The finished design showed a handsome three funnelled ship. At 4,700 tons displacement, they measured 436 feet long by 51 feet wide. 38,000shp through four screws gave a speed of 28 knots, with a range of 7,000 miles at 10 knots. The first four ships were laid down in 1907, with a repeat classes of four ordered in 1908 and a further two ships in 1909, for an eventual ten ships of the class.