This study presents a practice-based research project to develop a colour tool prototype intended to convey colour research to design practice. Both the prototype design and its evaluation by experts are described. A web-based prototype for a colour tool was cocreated with eight experienced designers and brand managers. The developed prototype is a visual and interactive website that predominantly provides research data on colour meanings in different product categories and cultures. In the evaluation study, an e-mail survey of experts was conducted to assess the prototype. A senior manager at a leading US colour company and seven academics in the fields of colour, branding and graphic design participated in the survey. As for the results, the prototype generally was deemed useful for design practice. The outcome also emphasized that the prototype has strong potential to play a significant role in providing colour insights and supporting colour judgments, strategy and inspiration. However, the experts also raised several issues concerning the data's scope, an insufficient number of prototype web pages, product category choices, legal issues, data presentation method, data source clarity, and data management. The study's findings provide insight into how colour research can be delivered to design practice using a colour tool.