Recent publicized reports based on the use of the Farnsworth Panel D-15 test suggest that a large percentage of young children have a deficiency of blue vision (tritan type). In our study, 413 school children (ages 3 to 10) were tested with both the Farnsworth Panel D-15 test, as well as the A.O. H-R-R plates. None of the children failed either test for blue-yellow vision when traditional scoring instructions were observed. As in previous reports, we find that the children make a number of minor errors which adults rarely make. These errors show marked age-related patterns, being more frequent in younger children. However, further analysis of these errors revealed that the relative frequency with which particular error types were made on the D-15 test was significantly correlated with the existing perceived color difference data for the visually normal adult population. In addition, retesting significantly reduced all error types and reversing the test sequence demonstrated that most of the minor errors were made in the last half of the test regardless of the color vision task. The overall increase in the number of minor test errors seen with young children seems unrelated to color defects. The modified scoring methods in conjunction with the characteristics of the Panel D-15 test design account for the high percentage of errors classified as errors of blue vision.