The purpose of this true experimental, posttest-only control-group design was to determine if the color coding of exterior letters affects the fluency and decoding ability among fourth grade students who were below grade level in reading. If color coding exterior letters is an effective intervention, then struggling readers could utilize this intervention to improve their reading fluency and decoding abilities. Participants were selected from a random sample of 102 public school students who were below grade level in reading. The participants were from a district in the southeast United States. Each student was randomly assigned to either an experimental or control group. Both groups received identical tests from the Houghton Mifflin (2009) diagnostic assessment in real word decoding, pseudoword decoding, and fluency, except that the exterior letters of words were colored blue for the treatment group, while all letters were black for the control group. The real word decoding assessment revealed no statistically significant difference between the mean scores of the control group and treatment group. There was a statistically significant difference between the mean scores of the control group and treatment group for the pseudoword decoding assessment and fluency assessment. While current research indicates that the exterior letters of a word play an essential role when reading, based on a review of the literature, including searches from ERIC (Ebsco), ETS Online Research Library, Education Research Complete, Children's Literature Comprehensive Database, and ProQuest Education Journals, there are currently no color interventions that assist readers in focusing on exterior letters. Future research should focus on conducting follow up studies on the effectiveness of this intervention and test the effectiveness of color coding other morphological elements of words. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]