Color accuracy is relative. If you are seeking a machine that will exactly reproduce GREEN at exactly 5200 Angstroms you may have to invent the video processor. Replication of "visual acute color" between 3850 Angstroms and 7175 Angstroms (extreme limits) will NOT be exactly the same between any two displays or any two machines. Ambient light also slightly alters "perceived" color. ASUS UX501 machines are EXCELLENT and reliable!! The display can be operated in three different modes each of which results in perceived differences in color for a given interpretation of the three primary colors of pure yellow, pure red, and pure blue. Spectraview will change emitted wavelength a few hundred angstroms in any machine. If you are so concerned about color replication exactness to NIST standards take your machines to a licensed photometric lab and have the emission measured at each operating mode in a certified non-reflective standard ambient condition. One can and should ONLY be critical if data is presented comparing light emission wavelength based on reference to an emission standard.