Multiprimary display are now widely researched and used. There is little research concerning color temperature design, namely the relationship of the primaries. It is easy to design the relationship in three-primary display, because that is a simple 3 X 3 matrix inversion. But it is difficult when the number of primaries gets to be more than three, because the coefficient matrix is not in a square form, which always yields at? infinite solution set. This article presents a method to design the relative primary luminances of multiprimary color display. It will be useful in the multiprimary color laser projection or multiprimary color LED-based backlighting LCD display. (C) 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 201-204, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20483