IRLA is an instructional framework focused around student placement in a "color" reading level. Every grade level has a required level (or set of levels). The levels are built around grade level standards in reading fluency, comprehension and foundational skills. Foundational skills=phonics.
Data is collected on students reading proficiency on a website called School Pace.
The link below is a collection of resources for levels Yellow through Orange.
http://wges.pasco.k12.fl.us/?page_id=11260