Product perception is a core dimension of ergonomics, encompassing how individuals cognitively and emotionally interpret product attributes. Eyeglasses, as a salient and prevalent facial appearance-related product for children, whose self- and peer-perceptions are both complex and influential. Yet, how these perceptions shape children’s preferences remains underexplored. Moreover, colour represents one of the most immediate product attributes, which is associated with gender. Accordingly, this study investigates the mechanisms linking children’s emotional perceptions to their eyeglasses colour preferences, both boys and girls. A quantified hierarchical perception model was developed through a psychological experiment with 32 children (17 boys, 15 girls) and subsequent statistical and regression analyses. Using eyeglasses as a representative case, the model offers practical and quantitative guidance for colour design in facial appearance-related products. Overall, the study contributes to advancing knowledge of children’s perception and decision-making in the domains of colour, ergonomics, and product design.