Digital painting is an increasingly popular medium of expression for many artists, yet when compared to its traditional equivalents of physical brushes and viscus paint it lacks a dimension of tangibility. We conducted observations and in- terviews with physical and digital artists, which gave us a strong understanding of the types of interactions used to create both physical and digital art, and the important role tangibility plays within these experiences. From this, we developed a unique liquid-like tangible display for mobile, digital colour mixing. Using a chemical hydrogel that changes its viscosity depending on temperature, we are able to simulate the tangible feeling of mixing paint with a finger. This paper documents the information gathered from working with artists, how this process informed the development of a mobile painting attach- ment, and an exploration of its capabilities. We then document the feedback gathered from the artists, after returning with the prototype. We learnt it provided them with sensations of oil and acrylic paint mixing, while also successful mimicked how paints are laid out on a paint palette.