## 1 Introduction  
Within the current highly competitive marketplace, how to induce emotional resonance is crucial to a successful product design. A product's appearance is evaluated according to its overall image. A product with a favorable appearance requires the selection of the optimal combination of various design factors, such as form, color, texture, interface and line elements. The form of a product is defined by the relationships between a product's style, expression and function; modifying or emphasizing a product's volume or shape can attract the attention of consumers [1]. Additionally, an effective method is required to help designers present their design concept and elicit responses from consumers [2; 3].  
Color has a strong effect on us, beginning in childhood, and it can have highly emotional and symbolic associations when used in fashion, and even when used to emphasize form. Some studies have demonstrated that product color has a greater effect on the consumer perception of a product than the product form [4]. Color planning has been extensively studied, and has been adopted in product design [5; 6; 7; 8]. For consumers evaluating an overall product image, color and form are mutually dependent.  
If designers could follow a design guideline or a reliable information system to match a product with a color (or colors), based on the information from a large-scale survey, then they could achieve close to an optimal color design for customized product design services.  
Sports shoes are a classic example of the mass customization of popular products. Recent studies have investigated variations in the manufacture of shoes. For instance, [PERSON] proposed a size recommendation framework based on both 3D (foot and last) features and user preferences and provided a predictive model of the comfort levels for particular parts of the foot on the basis of the given size recommendation [9]. [PERSON] and [PERSON] classified the foot shapes of Taiwanese people using 3D foot scanning data; they asserted that women have a longer ball of foot length than do men (0.2% FL), and that when comparing feet of the same length, men have a longer breadth, girth and height, but a shorter toe height than do women [10]. [PERSON] et al. used principal component analysis and factor analysis to determine consumer preferences and perceptions of casual footwear [11]. [PERSON] et al. applied fuzzy set concepts to build a jogging shoe prototype expert system [12]. [PERSON] et al. combined a decision tree model, a k-nearest neighbor (KNN) model, and a neural network (NN) model, to present a prototype web application for providing suggestions for children's shoes [13]. Taken together, these findings provide useful information for shoe development.  
In the author's previous study, partial least squares (PLS) and neural networks were introduced to explore shoe form design factors and consumers' image perceptions [14]. In a subsequent study, the author used Kansei engineering steps, semantic differential rating, and statistical tools, to investigate the consumer psychology, perception and aesthetics in relation to sports shoe colors [15].  
To follow up, this study presents an in-depth hybrid neurogenetic optimization methodology based on ANNs and GAs to build a product color design prediction framework for shoe designers, by integrating customers' feelings regarding form and color in shoe samples. The NN is used to learn the experimental values obtained from experimental samples using Kansei engineering. Sports shoe design factors are used as the input parameters of the NN.  
The nonlinear relationship between consumers' perceptions of a shoe's image and its color scheme is determined by the NN, whereas the GA is employed to search the optimized NN's architectural parameters.