This article describes two color matching experiments using 6 displays and a visual trichromator based on spectral tunable LED technology respectively. Ten observers performed the experiment. The results were used to reveal observer metamerism between displays, to derive each individual’s color matching functions (CMFs), and to test their performance against the available CMFs. Comparing different CMFs to estimate observer metamerism of displays, individual CMF (expressed by mean ΔE00 of 2.7) clearly outperformed the others. Amongst the CIE CMFs, CIE 2006 10° performed the best (5.1), followed by the other color matching functions, CIE 1931 2° gave the worst performance (11.1). The results indicates a large error could occur by adopting the current standard (CIE 1931 2°) to specify colors and this can be much improved using the individual CMFs. A simulation analysis of display primaries was also conducted to show peak wavelength to have a greater impact on observer metamerism than peak bandwidth.