Signals to remember: investigating the retrieval function of colors

Learners often rely on visual cues, such as color highlights, to recall important information in instructional texts. Color can serve as an attention-guidance cue but also a memory cue to promote learning. However, research has not yet thoroughly explored how colors can serve both purposes: signaling relevant information within the learning material and serving as memory cues to foster retrieval during testing. Therefore, this study investigated whether different signaling colors in digital learning environments can serve as memory cues to enhance retrieval and improve learning outcomes for secondary students. In a 2 (signaling color: monochromatic vs. polychromatic) × 2 (memory cue presence: during learning vs. during learning and retrieval) between-subjects experiment, 168 participants learned about auroras in a digital learning environment, presented across five texts and seven instructional pictures. The study assessed learning outcomes, cognitive load during learning, and mental load and mental effort during testing, as well as prior knowledge. Results revealed no effects of memory cue presence or signaling color, nor any interactions. Additional Bayes factors largely supported the null hypothesis across all measures. Results are discussed in terms of both color encoding and superficial processing. Color-based signaling does not automatically function as a memory cue, highlighting the need for instructional approaches that promote meaningful cue encoding and consistent reuse across learning and assessment contexts.