If you take the former example:

Pat.AddColorStop 0.7, vbRed
Pat.AddColorStop 0.99, vbGreen
Pat.AddColorStop 1, vbBlue

Then the opposite direction would be this:

Pat.AddColorStop 0.3, vbRed ' = 1 - 0.7
Pat.AddColorStop 0.01, vbGreen ' = 1 - 0.99
Pat.AddColorStop 0, vbBlue ' = 1 - 1

Olaf