## 2 Materials and Methods
### Methodology  
This research integrates a total of three quasi-experimental frameworks (Figure 1), two of which incorporate a control group, systematically employing a pretest, two of them similar to the [PERSON] et al. [46] classification as an 'equivalent materials design' and the other with an incomplete counterbalanced design. Over three distinct intervals, and across several educational institutions (spanning both rural and urban settings), four assessments were conducted within each institution for each dependent variable and its respective dimensions: an initial pretest followed by three post-test assessments following the implementation of coloured light scenarios. These coloured light scenarios function as the dependent variable, using shades that align with the examinees as outlined by [PERSON] et al. [3]. The 'daylight' conditions and coloured light scenarios can be quantified in later sections and, in all cases, are realised by using LED bulbs in the colours recommended by [PERSON] et al. [3], which correlate with the shades typically observed in the natural environment. As noted in the introduction, the impact of classroom lighting (with respect to CCT and brightness) on academic performance, attention and emotional-motivational states id one of the most frequently addressed topics in academic discourse [2]. This observation is valid not only with respect to lighting as an isolated variable, but also with respect to colour as it is conventionally perceived as a physical element of the classroom environment [1]. Although it is not feasible to examine these aspects exhaustively, we consider attention (along with its intrinsic connection to the regulation of impulsivity) to be paramount; this assessment is based on its established importance within the scientific community and the increased attention it currently receives in historical and socio-cultural contexts, particularly in relation to minors [47]. Furthermore, we consider creativity to be of particular importance, especially as it is valued by educational policies in the western world, which emphasise cognitive processes derived from [PERSON]'s taxonomy as fundamental for optimal academic performance [36; 48]. Similarly, the fundamental instrumental learning processes highlighted in the legislation, mainly mathematical and linguistic skills [36], together with emotions frequently highlighted in the previous literature [3], are incorporated to form our dependent variables. Accordingly, we have assessed the following dependent variables, which we briefly summarise in Figure 2:  
* V1. Cognitive Processes: The present investigation will evaluate three of its dimensions (figurative creativity, attentional focus and regulation of impulsivity). Figurative creativity will be measured using four indicators: originality, elaboration, fluency and flexibility. Figure 1: Overview of experimental situations, looking at the three partial experimental situations from which the total data of this study are obtained. * V2. Instrumental learning: Two of its dimensions will be examined (written linguistic competence and mathematical competence). The score for written linguistic competence is derived from two indicators: written expression and written comprehension. * V3. Affective processes: Three of its facets will be analysed (level of satisfaction, energy level and feeling). The third facet is nominal; however, it will be converted into a numerical format for the purpose of statistical analysis. The instruments used for data collection have remained uniform throughout the three experimental situations and are as follows:  
* For the variable 'cognitive processes': [PERSON]'s creativity assessment documented by [PERSON] et al. [49], which encompasses four indicators (originality, elaboration, fluency and flexibility), in conjunction with [PERSON] assessment of attention, according to [PERSON] et al. [50], which presents the regulation of the attention network and impulsivity.