Recognizing emotions in children is challenging, particularly in child-centered design, as traditional self-report measures often fail to capture children's true emotional states. To address this deficit, we conducted a formative study to examine the accuracy of color-emotion associations and the effectiveness of auxiliary tools in supporting emotional expression. We explore the possibility of detecting children's emotion through their use of color in drawings, utilizing expressive arts therapy techniques. To do this, we curate a child-centered emotion-color dataset and perform assisted analysis to depict how children visually express emotions through color drawings. Afterwards, we proposed an application for caregivers to effectively perceive children’s emotions and conducted child-centered research to evaluate its effectiveness. Our analysis highlight the potential of integrating emotional detection tools into educational and psychological settings, facilitating early emotional recognition and intervention for children.