Option Explicit
Function Pond(ByVal R1 As Range, ByVal RL As Range) As Double
Dim T1(), TL(), C As Long
T1 = R1.Value: TL = RL.Value
For C = 1 To UBound(TL, 2)
Pond = Pond + Coef(RL(1, C)) * TL(1, C) * T1(1, C)
Next C
End Function
Function Coef(ByVal C As Range) As Double
Const Blanc = -4142, Orange = 44, Gris = 15, Mauve = 39
Select Case C.Interior.ColorIndex
Case Orange: Coef = 1.5
Case Gris: Coef = 1.75
Case Mauve: Coef = 2
Case Else: Coef = 1: End Select
End Function