To further facilitate the understanding of the ecodesign modelling and the approach allowing the calculation of different eco-coefficients, we think that it will be easy to formulate the problem by simply referring to Figure 3, which illustrates the synthesis of additive colours between the three primary RGB ones. For instance, the red colour characterises the set H (Health), the blue colour characterises the set Q (Quality) and the green colour characterises the set E (Environment). Moreover, combining these three primary colours in equal amount
yields white that characterises the subset F. Furthermore, superposing in equal amounts one of the primary colours with another colour gives a secondary colour; among them: yellow = red + green (subset D), magenta = red + blue (subset B) and cyan = blue + green (subset G). The total absence of colours yields the black, an empty subset, symbolised by 0.
The eco-coefficients а, в, Y may be located between as and 1, ps and 1, Ys and 1, respectively (i. e., as < a < 1; es < в – 1; Ys – Y – 1). The subscript "s" refers to sustainability, whereas as, es, Ys are sustainable coefficients, and their satisfaction measures are defined and established by sustainability requirements and eco-standards.
Table 1, shows in separate cases a rating satisfaction measure in the form of colour gauges when the events Q, H and E are independent and the values of а, в and Y are varying separately.
Table 1. Probability colour gauges for different values of а, в and y when Q-H-E aspects are independent
On the other hand, Table 2 illustrates an example in which the Q-H-E aspects are dependent, a is fixed while P and у are varying simultaneously.
Table 2. Probability gauge for the eco-coefficients а, в and у when Q-H-E aspects are dependent
From this primary analysis, it would be advantageous to exploit interesting results through the mixing additive colours technique when using the analogy between probability theory and code colours (Attaf, 2009). This technique can help designers and analysts involved with high-technology composite materials to easily understand the ecodesign approach and provide them with a strategic vision to reduce the negative impacts and assess the Q-H-E performances during the composite product life-cycle.