\(\begin{align} &C_1 = \text{hypot}(a_1,b_1)\\ &C_2 = \text{hypot}(a_2,b_2)\\ \\ &\Delta a = a_1-a_2\\ &\Delta b = b_1-b_2\\ &\Delta C = C_1-C_2\\ &K_1 = \begin{cases} 0.048&\text{textiles}\\ 0.045&\text{graphic arts} \end{cases}\\ &K_2 = \begin{cases} 0.014&\text{textiles}\\ 0.015&\text{graphic arts} \end{cases}\\ \\ &\Delta L = L_1-L_2\\ &\Delta H = \sqrt{\max\left(\Delta a^2+\Delta b^2-\Delta C^2,0\right)}\\ &K_L = \begin{cases} 2&\text{textiles}\\ 1&\text{default} \end{cases}\\ &K_C = 1\\ &K_H = 1\\ &S_L = 1\\ &S_C = 1+K_1C_1\\ &S_H = 1+K_2C_1\\ \\ &\Delta E = \sqrt{ \left(\dfrac{\Delta L}{K_LS_L}\right)^2+ \left(\dfrac{\Delta C}{K_CS_C}\right)^2+ \left(\dfrac{\Delta H}{K_HS_H}\right)^2} \end{align}\)