Human color vision differs from person to person, not only when color deficiencies occur but also within color-normal populations. Investigating individual variability in normal color vision is beneficial both for clinical purposes and for quantifying observer metamerism. Researchers have used color matches such as Rayleigh matches, Moreland matches, the D&H color rule, and various combinations of different media for such investigations. However, none of them were originally aimed at investigating the interobserver variability in color-normal populations, but rather were aimed at screening for color-deficiencies. The objective of this study was, therefore, to design and carry out a color matching experiment where observer variability appeared as large as possible to detect the interobserver differences in the color-normal population. Color matching was simulated under different combinations of reference spectrum and matching primaries using ColorChecker patches, different display/projector primaries, and the Stiles and Burch 49 observers. The simulation results showed: (1) The choice of spectra for the matching primaries had a significant effect on observer variability, (2) observer variability was large for near-neutral reference colors, and (3) observer variability in the lightness direction was small relative to chromatic variability. The color matching experiment highlighting interobserver variability was designed based on these three findings and carried out for 61 color-normal observers. Typical interobserver variability was 9.2 mean color difference from the mean (MCDM) using CIEDE2000 (spanning about 40 CIELAB units), which was much larger than any previous experiment. The obtained color matching data are useful for derivation, validation, and analysis of color matching functions. (C) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 530-539, 2016; Published Online 23 June 2015 in Wiley Online Library (wileyonlinelibrary.com).