The TriScape100 is a colour snapshot imager primarily designed for earth observation applications as a payload for CubeSat satellites. It is based on a 12.6-megapixel CMOS image sensor with an integrated Red Green Blue (RGB) Bayer filter in the visible spectral range. The TriScape100 provides snapshot imaging with a frame rate of up to 180 frames per second. The optics have a large aperture diameter and long focal length within a compact form factor, resulting in a ground sampling distance (GSD) of 4.75 m at an orbit height of 500 km. The modified Cassegrain optical design brings performance to the edge of the object field over the whole spectral range at an ultra-low distortion. The TriScape100 is engineered to withstand the rigours of the space environment and maintain performance across a wide temperature range. Its compact form factor is optimised for integration into 3U or larger CubeSat structures.