This quantitative study examined the effects of stored color knowledge on learning achievement and cognitive load using a randomized pretest-posttest control group design. Social media was used to recruit 60 adult participants, randomized into control and experimental groups. A multimedia lesson was presented where the control group viewed images with congruent colors applied, and the experimental group viewed images with incongruent colors applied. Lessons applied seven of Mayer's principles for computer-based instruction for optimal design. Principles used include the spatial contiguity principle, temporal contiguity principle, coherence principle, modality principle, redundancy principle, and the individual difference principle. Learning achievement was measured using a pretest and post-test, and cognitive load was measured using the standard Leppink et al. subjective survey. Multiple paired-sample t-tests were used to analyze the pretest and post-test, and a MANOVA was used to analyze cognitive load. Findings showed that the control group had significantly higher learning achievement and higher germane load than the experimental group. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]