This study was conducted to explore the role and significance of color in illustrations in picturebooks. For this, we analysed 19 picturebooks. Illustrators use black and white pictures to express fantasy space, moment of dream, or retrospective memory beyond the real world. In black and white picturebooks, the boundary between reality and fantasy is blurring. And the characters are described in equal relationships where a kind of unity is created on the basis of unbelievable empathy. Illustrators colours the only object on the basis of black line drawing on the white background to focus reader`s attention on it. This colouring method not only manipulates reader`s stance, but also adds density of the work. In this case, the theme of picturebook is character`s transformation or development. Besides, this colouring method suggests what more critical meaning over surface layer of the text is. Illustrators use color as a visual sign of character`s identity. Colors reflect not only the relationships among the characters, but also the character`s feeling, personality and narrator`s point of view about character.