Laser display is one of the next generation displays with the highly pure reproduction of colors and larger color gamut than any other electronic displays. However, it is inevitable to get some color regions that cannot be reproduced with three primaries. So recently more than three primary controllers1 are developing. In this study, a set of new RGB primary covering all object colors exist in real world is proposed as the guideline on designing laser display. The color region of real world objects was firstly described by measuring some objects: 367 artificial objects and 86 natural objects. For the artificial objects, garments and electronic devices were chosen, and flowers and leaves were chosen as the natural objects. Most of the measurement data from the artificial objects are located within the Munsell color region, while an amount of measurement data from natural objects are not. As a result, the color region of real world objects was approximated with 1294 Munsell standard colors and some natural colors located outside of the Munsell region. The boundary covering the color region of real world objects was optimized as a triangle so as to include both of NTSC gamut and sRGB gamut as well as measurement data. As a result, the optimum wavelengths of RGB primaries were defined as 630nm, 537nm, and 468nm, respectively.