The present concept is a portable color sensor for measuring color of a substrate that includes a single flat printed circuit board with a top and bottom side which includes at least one LED light and one color sensor and at least one light pipe receiving light from the LED and transmitting it onto a substrate at an angle theta. It also includes a tube frame including an optical tube for receiving light reflections from the substrate and directing the reflections to the color sensor. The light pipes and the tube frame, are mounted and compression fit between the printed circuit board and a lower housing.