The 3.7/engine was an engine that really did not work out as GM had hoped and they abandoned it after one gen. Add in the bankruptcy it ended up a short run engine and really never was embraced by the after market,
While tone was joking with the photo an engine swap to a V8 may be the only real option. But that depends on where you live and the condition of the truck.
A exhaust, intake and programmer really will net you little gains If any worth while gain.
The First Gen Colorado did come with a 5.3L V8 engine as an option in 2009 to 2012.
I had both a 2005 and later ordered a 2010 with the 3.7 and found it was more than sufficient and is still in the family. The later Atlas 3.7 engines were work horses and passing on the interstate and hauling reasonable loads worked just fine.
No need to try any bolt on upgrades to try and urge more out of it.
The 242 Hp and 242 lb/ft of torque moved it along quite well even in the CCSB.
Those who actually owned one or more Colorados can best attest to it's durability and performance.
The 3.7L I-5 Atlas engines were better performing than the dismal 4.3L rough running V6 GM put into the 1998 to 2003 S-10 , small Blazers and Sonoma trucklet.
The seats were also wider and more comfortable than the 2nd generation.
The 2010 I bought is still in the family at +140K miles. No real issues and only brakes and tires replaced to date after +11 years.