To create the illusion of an extended virtual set, the parameters and characteristics of the foreground and virtual background need to match. Some parameters like movement and parallax can be homogenised by tracking and synchronisation. This talk will closely examine the colour match between foreground and background in a Virtual Production Stage. At first sight, colour matching might be seen as a 'calibration problem', but we will show that it is hard to predict before shooting. Colour matching on the shooting day must be fast, robust and easy to achieve because principle photography is a pressures time. Also, the production might not afford an expert only for this task. Hence, the tools for colour matching need to be very intuitive, fast to learn, and easy to operate.