Sub test()
Dim t() As Date, i As Integer, d As Date, c As Range, coul() As Variant
ReDim t(0 To Range("A65536").End(xlUp).Row - 1, 0 To 1)
For i = 0 To Range("A65536").End(xlUp).Row - 1
t(i, 0) = Range("A" & i + 1).Value
t(i, 1) = Range("B" & i + 1).Value
Next i
coul = Array(3, 11, 6)
For i = 0 To Range("A65536").End(xlUp).Row - 1
For d = t(i, 0) To t(i, 1)
For Each c In Range("D6:G36")
If c = d Then c.Interior.ColorIndex = coul(i): Exit For
Next c
Next d
Next i
End Sub