## 3 Results
### Results on the Visual Experiment
Despite the presence of a few outliers and the slight overlap between the lower whisker of CAAD and the upper whisker of sRGB, the interquartile ranges remain completely separate, highlighting a marked difference in overall performance between the two models. Overall, the experiment demonstrates robust performance by effectively capturing substantial differences between the methods being compared. To further validate the results, intra-observer repeatability and inter-observer reproducibility were determined. The intra-observer repeatability is calculated as the average absolute difference between the visual score given by an observer for a particular color in a particular session and the corresponding value for that same combination of observer and color after averaging over all three sessions. This quantifies how repeatable a visual score is for a particular observer-color combination. After averaging this for all observers and colors, the result is an intra-observer repeatability of 0.36 for color representations calculated using sRGB color space and 0.47 for CAAD. The inter-observer reproducibility is calculated as the average absolute difference between the visual score given by an observer for a particular color (averaged over three sessions) and the corresponding value for that same color after averaging over all observers and all their sessions. This quantifies how reproducible a visual score is for a particular color. After averaging this for all colors, the inter-observer reproducibility is 0.42 for color representations calculated using the sRGB color space and 0.57 for CAAD model parameters. The observer data contain a set of 720 assessments about which of the two digital color representations was preferred by each observer for every sample in each session. In 97.4% of the evaluations, observers preferred the color representation calculated with the CAAD model. It is important to emphasize that the observers were unaware of which method had been used for each image. The visual data also contains 720 visual scores for the color accuracy of digitally representing the physical samples using sRGB color space, and 720 visual scores for the case  
Figure 6: Boxplot of the scores for methods sRGB and CAAD. where the digital color representations are calculated with the average Apple parameters. Table 7 shows a large difference in visual scores when using the CAAD model versus when using the sRGB color space. The average visual score improves from 4.33 to 1.29 by using the CAAD. A different measure to investigate the two color reproduction accuracies is to calculate the percentage of visual scores that are 4 or higher. Based on the scoring scale shown in Table 2, these scores refer to poor color matches between the digital color representation and the physical sample. When using sRGB color space to calculate digital color reproductions, in 85.3% of the evaluations, the color match is rated as not correct or even very bad. Table 7 shows that this percentage shrinks to 4.9% when using the CAAD model. A related measure is the percentage of visual scores that are 2 or smaller. This may be viewed as the percentage of color matches that is reasonable or better. This percentage increases from 4.0% when using the sRGB color space to 84.2% when using the MDCIM with averaged Apple parameter values.