The visual factor for interior design affects comfort of trains and sitting comfort of seats is important because passengers sit on seats for long time. In this study, we focused how the seat color influences sitting comfort. First, we carried out an experiment to prepare graphics of seat colors. Next, we conducted sensory tests on display to assess images of seat colors. Finally, we fabricated train seat covers of green and blue colors and performed sitting experiments to examine the visual influence of seat color on sitting comfort. As the results, evaluation about touch feeling improved over time on green colors. Not only evaluation scores of touch feeling but also those of relaxation feeling increased over time on blue colors. Therefore, it is assumed that seat colors affect sitting comfort and this effect is different by color types.