Background. Early childhood cognitive development and early literacy are crucial for building logical thinking and understanding symbols and written language. During the golden age (ages 4-6), brain development peaks, making appropriate stimulation essential. However, innovative learning approaches for children aged 4-5 remain limited. Preliminary observations at Muslimat NU Nurul Islam Kindergarten (Kudus), Islam Plus Khozinatul Ulum Kindergarten (Blora), and Raudhotul Athfal Hidayah (Pati) showed that teachers mostly use conventional worksheets without attractive color variations, resulting in low attention, boredom, and less meaningful learning. Previous studies have examined color-based or worksheet-based interventions separately, but few have integrated color-coding strategies with cognitive and early literacy objectives in a single, developmentally appropriate product. Purpose: This project aims to develop and validate Color-Coded Number Worksheets (LKABW) to support cognitive development and early literacy in children aged 4-5 years. Method: This research and development (R&D) study used the ADDIE model at three locations involving 57 children. Data were collected through surveys, observations, and documentation using teacher questionnaires, observation sheets, and feasibility questionnaires. Media and material experts validated the product, followed by small-scale implementation and evaluation of feasibility and practicality. Results: LKABW achieved very feasible scores from media experts (94.6%) and material experts (100%). Observations of cognitive development and early literacy reached 81.2%, and teacher responses reached 99.2%. These findings indicate that LKABW is feasible and shows potential to support cognitive development and early literacy. Conclusion: This research advances early childhood education by offering an innovative, practical, and colorful alternative to conventional methods, integrating color-coding strategies with cognitive and early literacy activities. Further experimental research with larger samples is recommended to test its causal effectiveness and long-term impact.