In the design process, selecting colours and creating a palette is usually done digitally or with two-dimensional samples. However, when it comes to product design, the colour of the product is made and manufactured in the physical three-dimensional space, and will be perceived differently than in a digital presentation or on a physical surface. This study aims to investigate the significance of colour choices and highlight the difference between the perception of subtractive and additive colour on three-dimensional objects. It also emphasizes the importance of artistic training in design education.The study involves creating an interactive object that embodies a function, has a recipient in mind, and a context chosen by the user, which is clarified through the specific colour selection. These objects are known as "form ghosts" because they are low-fi and resemble products but with minimal detail and design features. The task requires working systematically to provide reasoning for one's results and presenting a well-developed colour proposal that aligns with the product.The goal of "form ghosts" is to shift the focus from form creation to the process of developing a colour proposal. It is worth considering if the lack of refinement in the form ghosts leads to simplified colour choices. Nonetheless, utilizing form ghosts as a tool in the colour process can be a first step in comprehending and reflecting on the appearance of a hue on a three-dimensional object in a physical context.