How to cycle through borders in Excel and change their color

I am trying to figure out a way to cycle through active borders in Excel and to change their colors to "next one" with each macro run.

Here is the code I've got:

Dim Color1 As Variant
Dim Color2 As Variant
Dim Color3 As Variant
Dim Color4 As Variant
Dim Color5 As Variant

Color_default = RGB(0, 0, 0)
Color1 = RGB(255, 0, 0)
Color2 = RGB(0, 255, 0)
Color3 = RGB(0, 0, 255)
Color4 = RGB(222, 111, 155)
Color5 = RGB(111, 111, 111)

Dim cell As Range
Dim positions As Variant
Dim i As Integer

positions = Array(xlDiagonalDown, xlDiagonalDown, xlEdgeLeft, xlEdgeTop, xlEdgeBottom, xlEdgeRight, xlInsideVertical, xlInsideHorizontal)

For Each cell In Selection
    For i = LBound(positions) To UBound(positions)
        If cell.BORDERS(positions(i)).LineStyle <> xlNone Then
            If cell.BORDERS(positions(i)).Color = Color_default Then
                cell.BORDERS(positions(i)).Color = Color1
            ElseIf cell.BORDERS(positions(i)).Color = Color1 Then
                cell.BORDERS(positions(i)).Color = Color2
            ElseIf cell.BORDERS(positions(i)).Color = Color2 Then
                cell.BORDERS(positions(i)).Color = Color3
            ElseIf cell.BORDERS(positions(i)).Color = Color3 Then
                cell.BORDERS(positions(i)).Color = Color4
            ElseIf cell.BORDERS(positions(i)).Color = Color4 Then
                cell.BORDERS(positions(i)).Color = Color5
            Else
                cell.BORDERS(positions(i)).Color = Color_default
            End If
        End If
    Next i
Next cell

It works. It does not change the weight of the borders and it does not add new borders (only changes the existing ones). The issue is that when two cells are nearby, the outer borders are changes to "next+1" color, and the inner borders are changed to "next+2" color, as they are looped through two times...

I have been thinking about the solution to this for quite a while now, but I cannot find any way to solve it.

Anyone willing to help? Thanks!