Abstract: Apparatus for obtaining a desired tint comprising light colouring means in the form of a cylinder having a number of different regions of respective different colours forming a ring around the axis of the cylinder, and region which is neutral as regards colour, which forms a ring around the axis of the cylinder, and which is adjacent to all the coloured regions. A light source directs light towards the cylinder, an aperture defining a selected region of the cylinder which affects the light which creates the desired tint. First movement control means are operable to effect rotation of the cylinder about its axis to effect a change in the hue of the tint without changing the saturation thereof, and said second movement control means are operable to effect axial movement of the cylinder to effect a change in the saturation in the tint without changing the hue thereof.