Results

three of them displaying the RGB value equivalent to 3000K, and two with a varying RGB. The sections were touching each other, to identify if the colour discrimination differs when the colours are adjacent. (Figure 5.13, picture 2)

The graph (Figure 5.15) represents the results of the test. The X-axis stands for the correlated colour temperature expressed in Kelvin degrees. The Y-axis shows the most common answer (mode) from the participants represented by points given to each answer: 1. Same Colour: no perception on the variation, 2. Little difference: slightly variation, 3. Big difference: very noticeable variation.

In Step 1, participants were shown the same colour representing the correlated colour temperature of 3000K in both rectangles, 2 participants expressed there was a slight variation between both rectangles (answer 2). The rest of the participants identified correctly that there was the same colour (answer 1).

When the slides of 3030K and 3060K appeared, all subjects perceived the same colour temperature as the 3000K rectangle. Starting from 3090K onwards, subjects started perceiving a little difference, with 3 subjects claiming not to see any difference. From 3150 K to 3270 K only three participants noticed no difference, the rest of the subjects noticed a little difference. From 3330 K to 3510 K most participants noticed a big difference between the colour temperatures. As the Kelvin was decreased, the subjects increased notice of a difference. At values of 2970 K and 2940 K, subjects mentioned they did not notice any variation in the colour, where they were shown warmer values with a range of 60K from 3000K. From 2910 K to 2830K, six subjects mentioned there is a slight difference, while from 2790 K to 2700 K, all participants noticed there is a high difference in colour temperatures.

In Step 2 the subjects were shown mixed colours, with only one subject mentioning that there was a slight difference between two colour temperatures with the same value of 3000 K.

At 3030 K only 2 subjects perceived a little difference, however, at 3060 K, half of the subjects started to notice a change. From 3090 K to 3180 K the subjects noticed a small difference among colour temperatures, whereas from 3210 K to 3510K, subjects could notice a big difference.

As the colours changed to warmer temperatures, the subjects noticed changes between the colour temperatures with smaller variations in cor-

Figure 5.14 Test being performed