Undesired coloring phenomenon is one of the most important problems in ceramic sector. Six Sigma is the methodology that aims to prevent the nonconformance product by reducing the variation in the process with applying certain steps: measure, analysis, improve and control. In this study, the application of the first and second steps of Six Sigma on the floor tiles is given. 18 factors are defined as the effective key inputs on the color of tile with cause and effect diagram. As a result, 5 key inputs were determined as the most effective key inputs on the color parameters like L*, a* and b*. These selected key inputs will be used for experimental design and analysis to improve step. The reduction on the key inputs is important and necessary in terms of effectiveness since the number of experiment increase exponentially with respect to the number of factors.